TR-149 TECHNICAL REPORT A STUDY OF WAVE PERSISTENCE FOR SELECTED LOCATIONS IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA JOHN M. KIPPER, JR. and ELLIS J. JOSEPH Environment Branch ion Foy Oceanographic Analysis Division Se "% e é SS SEPTEMBER 1963 / SYS - U. S. NAVAL OCEANOGRAPHIC OFFICE fb. TA-[HY WASHINGTON, D. C. 20390 Price 65 cents ABSTRACT Wave persistence graphs were constructed from wave data obtained from lightships and ocean station vessels. An explanation and examples of how to interpret the wave per- sistence graphics are given. Aclimatological summary for the selected regions is supplied as a background for arriving at certain generalizations concerning wave persistence. Several applications of wave persistence data are cited. ACKNOWLEDGMENT The authors wish to express their indebtedness to Mr. Marvin D. Burkhart, whose helpful suggestions and continued inter- est made this publication possible. FOREWORD The duration of favorable and unfavorable wave conditions is of prime importance to shipping concerns for economic purposes, to coastal installations for protective purposes, and to the Navy for military expediency. When used simultaneously with other available information, wave persistence data are especially beneficial to forecasting personnel and shipmasters in ship routing and to design engineers in coastal construction. This is one of a series of reports published by the U. S. Naval Oceanographic Office in its continuous endeavor to improve the ship routing program and its deep concem for the safety of ships at sea. ita DENYS KNOLL Rear Admiral, U. S. Navy Commander U. S. Naval Oceanographic Office MNT O 0301 oo44L9? 2 iM iii ae Lo in ae i am oA wl » tea Ps ie a, Hada oF 4 Mr fis ; b , a4! ah ae ‘ ee Th Te yy nes CONTENTS WOOL G6 6 6 6 00 6 010 6 6 6 6 O16 6 OO O06 6 WLS Oi ILEMIRAS 6/50 6.000 0 66 06°6 6°60 0 5! 616 Introduction . ....+.s+.e-2«+se-e2er ee 2 © 0 Explanation of the Graphics .. . « « « « «© © « « e Lightships Along the East Coast of the United States Ocean Station Vessels of the North Atlantic. .... Lightships of the North Sea and Baltic Sea ..... Application of Wave Persistence Graphics ...... holley? 50 5665005006 Oo 6 OOOO oo ee @ Figure LIST OF FIGURES al e Wave Hei ght Pro file e e e e e ° e e e e e eo e e e 2. Location Chart of East Coast Lightships . . . « » + © « « « 3. Wave Persistence Curves and Wave Height Bar Graphs for he East Coast (U. S.) Lightships . . ss se + eee ees GQHEA yeavVAn S&S Ke Portland, Maine - 3°48.L'N, 70°5.5'W ... . Pallock Rip, Mass. - 1° 36.1'N, 69°51.1'W. . Nantucket Shoals, Mass. - 0°37. O'N, 69°18.5'W Buzzards Bay, Mass. - 1°2h.0'N, 70°3. Ow. . Ambrose Channel, N. Y. - 0°27. LN, 73°h9.b'W Barnegat, N.J. - 39°5.8'N, 73°56. OW etc Five Fathoms Bank, N.J.- 38° 7 .3'N, 7h°3.6'W Chesapeake, Va. - "36° 3870, 7S De AUT 5 6 Diamond Shoals, N.C. - 35° 05. 3'N, 75° 19. TOW Wee Frying-pan Shoals, N.C. - 33 °28'N, 77°33.8'W . Savannah, Georgia - 31°56.6'N, 80° SIG SU 6 6 6 Location Chart of Ocean Station Wega Gh ewe cds 5. Wave Persistence Curves for Ocean Station Vessels 6 7 North Atlantic > e HeoOmsoow . Location Chart of North Sea and Baltic Sea ay gheehinns OSV "A" — 62, OSV "BY" - 56. OSV "Cc" — 52. osv "Dp" - bh. 0 OSV "E" = OSV "HY - OSV "I" . osv "J" — osv ™" . 66. °N, 33.0'W . ie ro) = e e e e e ° e e ° Wu1w Ww LS) x2) ONS. ~~ = »e) e (2) = ° e e e e ; 02. 0°E e e e e e ° ft 6 se) <0: “eo ve 16) 10) “0 (Oye se: te. “eo: Ve eeee¢ e@ e @ e eo © © 6 © © © @ @¢ «© Fre © @ @ “e ¢ @ eco . Wave Persistence Curves for North Sea and Baltic Sea Mala 5 56 6 6 set ee 8 A, B, Cr D. E. 16 S-2 5h°0. 5'N, 03° 3205 5 oo P-15/12 Sh°OO'N, O7°SL'E . . P-11/8 5° 16'N, Ovalales S'R : Elbe 5h°00'N, 08° 10.7'E .. Kiel 5°29. 9'N, NOMIUIIS 4g Fehmarnbelt Ele 36'N, 11°09'E e e eo eo e ) e e e e eo vi Oe: 5@- Cie 10S 40) 10. (eFsce. Oy) Je; 1 @ Page A STUDY OF WAVE PERSISTENCE IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA INTRODUCTION Little information has been published on the persistence (duration) of storm waves or time length of continuous spells* of low waves. It is often advantageous to know the expected duration of adverse wave condi- tions, since many mrine operations become ineffective or restricted when waves reach or exceed a certain height. Conversely, for specific marine activities it may be important also to know the duration of waves lower than a particular height category. To serve these needs, two sets of curves have been prepared for selected lightships and ocean station ves- sels for each of the four seasons. The selected stations are grouped regionally for reasons of climatology and textual presentation. Seasonal frequency of occurrence of selected wave height categories is furnished in bar graph form to provide additional information on the wave climatology at each of the selected locations. EXPLANATION OF THE GRAPHICS Only observations made over an unbroken period of time from stationary ships can be used to provide information on wave persistence. The informa- tional data gathered for this report were obtained from continuous records taken at the lightships and ocean station vessels. The longer the period of continuous record, the more reliable is the graphical mean. In this study, a minimum of three years of continuous record was considered adequate. In Figure 3 the set of curves labeled "Persistence of Favorable Waves" indicates the number of times during a season that waves decrease to less than specific height categories. These curves also show how long waves are expected to remain below the specified heights. The other set of curves labeled "Persistence of Unfavorable Waves" indicates the number of times during a season that waves increase to specific height categories or exceed them; they also show how long waves can be expected to exceed the specified heights. In each set of curves the number of occurrences of waves of each height category is expressed as the average number of occasions during the season that waves decreased in height below or rose to equal or ex- ceed a specific height. Since percentages are based on the average number of occasions that waves of the lowest height category were observed during a season, it is possible for the number of occasions for the higher height categories during the same season to exceed 100 percent. As an example, in the curves for Frying-pan Shoals Lightship (Figure 3J) for autumn the number of occasions of 6 ft. height category waves exceeds *Spells are based upon an analysis of 2-, 3-, h-, or 6-hourly observations. those of 3 ft. height category waves by about 25 percent, However, the combined durations of the occasions when waves are>6 feet never can exceed the combined durations of wavesS3 feet. These facts are readily seen in the smoothed wave profile shown in Figure 1. The various interpretations of the persistence curves can be made by consulting the legend. As an example, suppose one is interested in knowing how many times during the summer at Portland Lightship waves will be less than 6 feet high continuously for at least 5 days (120 hours). Reference to the appropriate set of curves in Figure 3A shows this to be about 10 percent of 8 (Point A), or about 5 times during the season. Similarly, suppose one wants to know how many times during the winter at Portland Lightship waves will exceed 6 feet for at least 2h hours. Again, reference to the appropriate set of curves in Figure 3A shows this to be about 13 percent of 3 (Point B), or 5.6 times, i.e., between 5 or 6 times during the season. Reference to the examples on the legend will suggest other ways in which the curves can be“used. Certain generalizations as to the seasonal variability of waves at the lightships and ocean station vessels also are evident from comparative studies. To illustrate, the durations of favorable waves generally are longer than those of unfavorable waves, particularly in summer. The bar graphs associated with each persistence graph give the total relative frequencies of occurrence seasonally for each wave height category. 3WdOdd LHOIZH JAVM | SYN! (SYNOH) NOlWVvuna 80L 96 v8 cL 09 8 9€ vZ ZL 0 “SNOISVDDO @ NO 13434 Zl GNV 1334 € NVHL YaLV3YD YO OL IWNDA ANV ‘SV3YV G3lddIlS AG GILVIIGNI SV ‘SNOISVDDO € NO 13346 GNV 1334 9 NVHL ¥3lVad¥D YO OL 1VNOI 3YSM SLHOISH JAVM ‘J1dWVXA SIHL NI Mite (1334) LHOISH LIGHTSHIPS ALONG THE EAST COAST OF THE UNITED STATES A major storm track (along which there has been a maximum concentra- tion of individual storm paths) prevails along the east coast of the United States during the late autumn, winter, and early spring. The winds of the individual storms largely determine wave conditions. Hence, maximum fre- quencies of wavesS5 feet occur approximately along the axis of the major storm track from the Carolinas to Newfoundland. However, because migratory storms generally move through this region at moderate rates of speed, the persistence graphs in Figures 3through 5 show that durations of unfavorable waves are shorter than those of favorable waves. In addition, the influence of prevailing westerly component winds (offshore winds) on unfavorable wave generation is minimized by the sheltering effect of the continent; i.e., the fetch distances are short between the shoreline and the lightships. An exception occurs at Frying-pan Shoals Lightship, where unfavorable waves persist through spells in excess of 300 hours. This is due mainly to the location of this lightship in a region of storm generation, where the lightship is subjected to lengthy periods of adverse waves before the newly generated storm moves out of the region. The east coast of the United States is so oriented that high swell waves from distant storms generally do not radiate toward it. On rare occasions, however, a meteorological situation arises whereby the forward progress of a deepening storm is temporarily blocked, and the low pressure cell may be forced into an east-to-west elongation pattern. The pressure gradient and subsequent strong winds over long fetch distances on the north side of such a stagnated storm produces high waves and directs an onslaught of successive high swell waves into the shore. A recent notable example was the destructive storm of 5-9 March 1962 along the east coast of the United States during which many places recorded a runup of waves 20 to 30 feet high for the period of surge accompanying this storm. In general, the east coast lightships (except Frying-pan Shoals Light- ship) experience longer durations of favorable wave conditions than unfavor- able wave conditions throughout the year, which reach a maximum during the summer season when the Azores high is at its westernmost extension and peak of influence. BUZZARDS BAY, MASSACHUSETTS AMBROSE CHANNEL @ NANTUCKET SHOALS, MASSACHUSETTS NEW Y ce aes NEW JERSEY @ FIVE FATHOM BANK, NEW JERSEY Se CHESAPEAKE, VIRGINIA Ty y/~@ DIAMOND SHOAL, NORTH CAROLINA 8 TS A a PORTLAND, MAINE | &c a _ JG 2 @ POLLOCK RIP, MASSACHUSETTS @ FRYING- PAN SHOALS, NORTH CAROLINA ad @ SAVANNAH, GEORGIA 7 FIGURE 2 LOCATION CHART OF EAST COAST LIGHTSHIPS LEGEND AND EXAMPLES aa 6552 OBSERVATIONS 6552 OBSERVATIONS 16-AVERAGE NUMBER OF OC- 16-AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW TO 3 FEET OR HIGHER. 3 FEET. WAVES DECREASED IN HEIGHT BELOW WAVES ROSE TO 9 FEET OR HIGHER 9 FEET AND LASTED 6 TO >300 HOURS AND LASTED 6 TO >300 HOURS ON 24 OCCASIONS (150% x 16)* ON 24 OCCASIONS (150% x 16)** DURING THE SEASON. DURING THE SEASON. = WAVES DECREASED IN HEIGHT BELOW 3 FEET AND LASTED 6 TO 48 HOURS ON 16 OCCASIONS (100% Xx 16) DURING THE SEASON. WAVES ROSE TO 3 FEET OR HIGHER AND LASTED 6 TO >300 HOURS ON 16 OCCASIONS (100% xX 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW 6 FEET AND LASTED 42 TO 144 HOURS | ON 8 OCCASIONS (50% X 16) DURING THE SEASON. WAVES ROSE TO 6 FEET OR HIGHER AND LASTED 36 TO >300 HOURS f | ON 8 OCCASIONS (50% xX 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW Piz ROSE TO 12 FEET OR HIGHER 12 FEET AND LASTED 180 TO >300 AND LASTED 48 TO 180 HOURS ON HOURS ON 4 OCCASIONS (25% x 16) 4 OCCASIONS (25% Xx 16) DURING DURING THE SEASON. THE SEASON. FREQUENCY OF OCCASIONS (PERCENT) = 74 a re) m4 wo oe on Zz 9 a < re) ro) fo) re fo) > ro) Zz G =) fe] ire) ce ir 100 120 140 160 180 200 220 240 260 280 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) 3 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) * IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES BELOW 3 %* * IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES 3 FEET OR FEET THERE ARE THREE CHANCES WAVES WILL BE LESS THAN 9 FEET. HIGHER THERE ARE THREE CHANCES WAVES WILL EQUAL OR EXCEED 9 FEET. LEGEND WAVE HEIGHT 0 10 20 30 40 50 60 70 80 90 100(%) SUMMARY SCALE (ALL DIRECTIONS) FIGURE 3 WAVE PERSISTENCE CURVES AND WAVE HEIGHT BAR GRAPHS FOR EAST COAST (U.S.) LIGHTSHIPS FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 1440 OBSERVATIONS 43 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 1440 OBSERVATIONS 43 AVERAGE NUMBER OF OC. 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) [opapere bisa O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 1456 OBSERVATIONS 51 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 |1456 OBSERVATIONS 51 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 0 100 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) hyo O 10 20 30 40 50 60 70 80 90 100 FIGURE 3A PORTLAND, MAINE 43°48.4/N., 70°5.5’W. FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 150 140 1840 OBSERVATIONS 140 +|1840 OBSERVATIONS 48 AVERAGE NUMBER OF OC- 48 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. no 10 100 100 FREQUENCY OF OCCASIONS (PERCENT) 0 PS Sa 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) Eater amsauaneena| O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 1820 OBSERVATIONS 140 1820 OBSERVATIONS 38 AVERAGE NUMBER OF OC- 38 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. no FREQUENCY OF OCCASIONS (PERCENT) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) Juan O 10 20 30 40 50 60 70 80 90 100 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 150 140 1440 OBSERVATIONS 140 1440 OBSERVATIONS 36 AVERAGE NUMBER OF OC- 36 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 110 110 = 100 & 100 g = 90 w 90 Zz ce) 80 2 80 g 70 oO 70 rs, fe) 60 > 60 Vv a 50 > 50 g 40 = 29 30 30 20 20 10 10 0 0 Ss = io) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) |p arerr 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 1456 OBSERVATIONS 36 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 130 120 ||1456 OBSERVATIONS 36 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 3 FEET. 110 300 100 FREQUENCY OF OCCASIONS (PERCENT) 300 t) 20 40 60 80 140 100 120 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 140 160 180 200 220 240 260 280 12 FT.) [spend eme 0 10 20 30 40 50 60 70 80 90 100 FIGURE 3B POLLOCK RIP, MASS. 41°36.1'N., 69°51.1’W. 10 200 220 240 180 160 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 no 100 150 no 100 JULY, AUGUST, SEPTEMBER 150 140 1472 OBSERVATIONS 140 1472 OBSERVATIONS 38 AVERAGE NUMBER OF OC- 38 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 110 FREQUENCY OF OCCASIONS (PERCENT) ) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) [rns O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 140 1456 OBSERVATIONS 140 1456 OBSERVATIONS 40 AVERAGE NUMBER OF OC- 40 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 0 100 90 80 70 60 50 FREQUENCY OF OCCASIONS (PERCENT) 40 30 20 10 0) (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 10) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 11 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 5040 OBSERVATIONS 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 5040 OBSERVATIONS 27 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 5824 OBSERVATIONS 37 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 824 OBSERVATIONS 37 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 40 30 20 10) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES(353,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 3C NANTUCKET SHOALS, MASS. 40°37.0/N., 69°18.5’W. 12 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 140 5888 OBSERVATIONS 35 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 3 FEET. 100 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 5888 OBSERVATIONS 35 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. no 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 140 5096 OBSERVATIONS 28 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 3 FEET. 10 100 te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 5096 OBSERVATIONS 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO FEET OR HIGHER. no 100 300 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES(53,6, 9, 12 FT.) [oem 10 20 30 40 50 60 70 80 90 100 13 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 150 140 1080 OBSERVATIONS 140 1080 OBSERVATIONS 32 AVERAGE NUMBER OF OC- 32 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 110 — 1 = Zz a 100 Y 100 = 90 2 90 i} 80 2 80 0 re) 70 © 70 re fe} 60 > 60 6) Z a 50 g 50 i = 40 40 30 30 20 20 10 10 = - 0 A A a es ke ° - o| ale 0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 te} 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) ym AN O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 1092 OBSERVATIONS 7|1092 OBSERVATIONS 32 AVERAGE NUMBER OF OC- 32 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW TO 3 FEET OR HIGHER. 3 FEET. no 300 100 FREQUENCY OF OCCASIONS (PERCENT) Ce) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) Jrnjuinpny O 10 20 30 40 50 60 70 80 90 100 FIGURE 3D BUZZARDS BAY, MASS. 41°24.0’N., 71°3.0’W. 14 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 100 150 140 130 100 1104 37 JULY, AUGUST, SEPTEMBER OBSERVATIONS AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 180 DURATION (HOURS) 728 32 200 220 240 260 PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) BUY OU CUCU 1 280 300 FREQUENCY OF OCCASIONS (PERCENT) 150 140 1104 37 OBSERVATIONS AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER OBSERVATIONS AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 150 140 130 120 110 100 100 120 140 160 180 DURATION (HOURS) 728 32 200 220 240 260 280 PERSISTENCE OF UNFAVORABLE WAVES(53,6, 9, 12 FT.) OBSERVATIONS AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) 120 140 160 180 DURATION (HOURS) 200 220 240 260 PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) 280 300 O 10 20 30 40 50 60 70 80 90 100 15 120 140 160 180 DURATION (HOURS) 200 220 240 260 280 300 PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 130 100 150 140 130 120 110 100 JANUARY, FEBRUARY, MARCH 150 140 1440 OBSERVATIONS 30 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 1440 OBSERVATIONS 30 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) 80 100 120 140 160 180 100 120 140 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) 200 220 240 260 280 300 () Jinru O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 1820 OBSERVATIONS 37 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 130 120 no 100 160 180 200 220 240 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 1820 OBSERVATIONS 37 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) 120 140 160 180 200 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) 220 240 260 280 300 to) 80 100 120 140 160 OOD COL Eu Eo © 10 20 30 40 50 60 70 80 90 100 FIGURE 3E AMBROSE CHANNEL, N.Y. 40°27.1/N., 73°49.4’W. 16 180 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 260 280 300 200 220 240 260 280 300 150 140 130 120 no 100 FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 no 100 FREQUENCY OF OCCASIONS (PERCENT) 1840 OBSERVATIONS 24 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. JULY, AUGUST, SEPTEMBER 150 140 130 1840 OBSERVATIONS 24 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) 120 140 160 180 DURATION (HOURS) 200 220 PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) 240 260 280 300 to) 20 OO CORY TEU POO ECU BLL | 10 20 30 40 50 60 70 80 90 100 {e} OCTOBER, NOVEMBER, DECEMBER 1820 OBSERVATIONS 3 FEET. 33 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 150 140 80 100 120 140 160 180 200 220 240 260 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 1820 OBSERVATIONS 33 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 280 300 FREQUENCY OF OCCASIONS (PERCENT) 100 120 140 160 180 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) 200 220 240 260 280 300 to) 20 frnnjrripien 10 20 30 40 50 60 70 80 90 100 fo) 17 120 140 160 180 200 220 240 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 1800 OBSERVATIONS 36 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. io) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 0 1800 OBSERVATIONS 36 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) [oy pene arl O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 130 1820 OBSERVATIONS 30 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 1820 OBSERVATIONS 30 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (33,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 3F BARNEGAT, N. J. 39°45.8’N., 73°56.0’W. 18 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 120 100 JULY, AUGUST, SEPTEMBER 1840 OBSERVATIONS 26 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) Happy eety O 10 20 30 40 50 60 70 80 90 100 150 140 130 120 110 100 1840 OBSERVATIONS 26 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) OCTOBER, NOVEMBER, DECEMBER 1820 OBSERVATIONS 32 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) frnpariypery FREQUENCY OF OCCASIONS (PERCENT) 1820 OBSERVATIONS 32 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 19 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 JANUARY, FEBRUARY, MARCH 3212 OBSERVATIONS 22 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 3212 OBSERVATIONS 22 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. () 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) APRIL, MAY, JUNE 140 3276 OBSERVATIONS 11 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 110 100 6 FEET. to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 3276 OBSERVATIONS 11 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. 110 © ° N °o o iS wo i) os ° 30 20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) FIGURE 3G FIVE FATHOMS BANK, N. J. 38°47.3’N., 74°34.6’W. 20 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 150 140 3156 OBSERVATIONS 140 3156 OBSERVATIONS 9 AVERAGE NUMBER OF OC- 9 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no en) S Zz Fr 100 y 100 = 90 3 90 Q 80 2 80 U Vv 70 oO 70 fo) 60 > 60 VY Zz 2 50 50 g = 40 30 20 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 10 0 . (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 ) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) OCTOBER, NOVEMBER, DECEMBER 3312 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 3312 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 300 to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) 21 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 110 100 150 140 120 100 JANUARY, FEBRUARY, MARCH 1440 OBSERVATIONS 32 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) 150 140 130 120 110 FREQUENCY OF OCCASIONS (PERCENT) 1440 OBSERVATIONS 32 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS ($3 6, 9, 12 FT.) © 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 1456 OBSERVATIONS 39 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) jo 150 140 130 120 FREQUENCY OF OCCASIONS (PERCENT) 1456 OBSERVATIONS 39 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 3H CHESAPEAKE, VA. 36°58.7’N., 75°42.2’W. 22 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 150 140 JULY, AUGUST, SEPTEMBER 150 1472 OBSERVATIONS 140 1472 OBSERVATIONS 35 AVERAGE NUMBER OF OC- 35 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. FREQUENCY OF OCCASIONS (PERCENT) = — 0 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) Jinn O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 130 1456 OBSERVATIONS 140 41456 OBSERVATIONS 31 AVERAGE NUMBER OF OC- 31 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 100 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 3 r=} S FREQUENCY OF OCCASIONS (PERCENT) 40 30 20 joasyexetere|ofeletelsls| plore ” B : 40 60 80 100 120 140 160 180 200 220 240 260 280 300 te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, 12 FT.) Jrnnyun O 10 20 30 40 50 60 70 80 90 100 23 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 JANUARY, FEBRUARY, MARCH 1440 OBSERVATIONS 26 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 1440 OBSERVATIONS 26 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 10 (°) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES(53,6, 9, 12 FT.) [ogee 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 1456 OBSERVATIONS 34 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 1456 OBSERVATIONS 34 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 3 FEET OR HIGHER. 10 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) © 10 20 30 40 50 60 70 80 90 100 FIGURE 31 DIAMOND SHOALS, N.C. 35°05.3’N., 75°19.7'W 24 JULY, AUGUST, SEPTEMBER 150 150 140 1472 OBSERVATIONS 140 1472 OBSERVATIONS 27 AVERAGE NUMBER OF OC- 27 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 10 o ° 80 N 3 N o o 3° o 3 FREQUENCY OF OCCASIONS (PERCENT) a 3 FREQUENCY OF OCCASIONS (PERCENT) ~~ So o °o n So 10 "5 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 °o 20 40 " 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) finn O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 1456 OBSERVATIONS 140 1456 OBSERVATIONS 21 AVERAGE NUMBER OF OC- 21 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. 3 3 tS) e = & FA 2 2 £ & 2 3 90 9° 9° oi} 2 80 8 8 ° © 70 u re fe) fe) > > 60 Vv 50 g g “40 30 20 NN 0 IN. t°) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 1) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES (<3,6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE WAVES (53,6, 9, 12 FT.) jin O 10 20 30 40 50 60 70 80 90 100 25 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, 1440 OBSERVATIONS 25 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 120 140 160 180 200 DURATION (HOURS) 12 FT.) 220 240 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) 140 130 120 FEBRUARY, MARCH 150 1440 OBSERVATIONS 25 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, [oper 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 1456 OBSERVATIONS 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 3 FEET. FREQUENCY OF OCCASIONS (PERCENT) 150 140 120 100 80 100 120 140 160 180 200 220 240 DURATION (HOURS) 12 FT.) 1456 OBSERVATIONS 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 3 FEET OR HIGHER. 260 280 300 200 220 240 260 280 300 to) 20 40 60 80 100 120 140 160 180 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<3, 6, 9, 0) — 2 260 280 300 t°) 20 40 60 80 100 120 140 160 180 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (53,6, 9, boomer 10 20 30 40 50 60 70 80 90 I00 200 220 240 12 FT.) 12 FT.) FIGURE 3J FRYING-PAN SHOAL 33°28.0’N., 77°33.8’W. 26 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 1472 OBSERVATIONS 140 1472 OBSERVATIONS 27 AVERAGE NUMBER OF OC- 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 3 FEET OR HIGHER. 3 FEET. FREQUENCY OF OCCASIONS (PERCENT) 40 30 150 300 20 10 my 300 HOURS CASIONS DURING THE SEA- AND LASTED 4 TO >300 HOURS CASIONS DURING THE SEA- ON 24 OCCASIONS (150% xX SON WHEN WAVES DE- ON 24 OCCASIONS (150% x 16)** BURINGRTTENGEACON DURING THE SEASON SON WHEN WAVES ROSE p CREASED IN HEIGHT BELOW Z TO 6 FEET OR HIGHER. 6 FEET. WAVES DECREASED IN HEIGHT BELOW 6 FEET AND LASTED 3 TO 144 HOURS ON 16 OCCASIONS (100% X 16) DURING THE SEASON. WAVES ROSE TO 6 FEET OR HIGHER AND LASTED 3 TO >300 HOURS ON 16 OCCASIONS (100% x 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW 6 FEET AND LASTED 10 TO 144 HOURS ON 12 OCCASIONS (75% xX 16) DURING THE SEASON. WAVES ROSE TO 6 FEET OR HIGHER AND LASTED 22 TO >300 HOURS ON 12 OCCASIONS (75% xX 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW 9 FEET AND LASTED 45 TO>300 HOURS ON 8 OCCASIONS (50% X 16) DURING THE SEASON. WAVES ROSE TO 9 FEET OR HIGHER AND LASTED 47 TO >300 HOURS ON 8 OCCASIONS (50% xX 16) DURING THE SEASON. = Zz a ie) 4 i Ss no Zz (e) a < re) w) ° wo ° > 6) Zz ry =) ie) uw m4 < FREQUENCY OF OCCASIONS (PERCENT) WAVES DECREASED IN HEIGHT BELOW WAVESIROGERTONIDIRCERORINIGHER see e eee eo ee Ores oe AND LASTED 46 TO 186 HOURS ON ROURSIONTAOCCASIONS|(25 (7.2316) 4 OCCASIONS (25% X 16) DURING DURING THE SEASON. THE SEASON. 160 180 200 220 240 260 280 300 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (56, 9, 12 FT.) * IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES BELOW 6 ** IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES 6 FEET OR FEET THERE ARE THREE CHANCES WAVES WILL BE LESS THAN 9 FEET. HIGHER THERE ARE THREE CHANCES WAVES WILL EQUAL OR EXCEED 9 FEET. LEGEND WAVE HEIGHT a Ss oat 0 10 20 30 40 50 60 70 80 90 100 SUMMARY SCALE (ALL DIRECTIONS) FIGURE 5 WAVE PERSISTENCE CURVES AND WAVE HEIGHT BAR GRAPHS FOR OCEAN STATION VESSELS OF THE NORTH ATLANTIC 33 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 150 140 5040 OBSERVATIONS 140 5040 OBSERVATIONS 17 AVERAGE NUMBER OF OC- 17 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. an Te) 100 100 FREQUENCY OF OCCASIONS (PERCENT) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) © 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 150 140 5096 OBSERVATIONS 140 5096 OBSERVATIONS 16 AVERAGE NUMBER OF OC- 16 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 110 100 100 FREQUENCY OF OCCASIONS (PERCENT) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5A OSV ‘‘A"’ 62.0°N., 33.0°W. 34 150 140 130 100 FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 0 100 FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 5152 OBSERVATIONS 13 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) bel a O 10 20 30 40 50 60 70 80 90 100 300 FREQUENCY OF OCCASIONS (PERCENT) 150 140 5152 OBSERVATIONS 13 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. 10 100 (°) 20 40 60 80 100 120 140 160 180 200 220 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, OCTOBER, NOVEMBER, DECEMBER T| 5096 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 300 FREQUENCY OF OCCASIONS (PERCENT) 150 240 260 280 12 FT.) 140 5096 OBSERVATIONS 10 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. no 100 160 180 200 220 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, [ep A 10 20 30 40 50 60 70 80 90 100 35 240 260 280 12 FT.) 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 100 150 140 130 120 100 JANUARY, FEBRUARY, MARCH 6380 OBSERVATIONS | 12 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 6380 OBSERVATIONS 12 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. 100 oO 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 6552 OBSERVATIONS 17 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. OF ~— 40 60 80 100 120 140 DURATION PERSISTENCE OF FAVORABLE — — — — _— 160 180 200 220 240 260 280 300 (HOURS) SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 6552 OBSERVATIONS 17 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. 110 100 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5B OSV ‘“‘B"’ 56.5°N., 51.0°W. 36 JULY, AUGUST, SEPTEMBER 150 150 140 +|6624 OBSERVATIONS 140 6624 OBSERVATIONS 20 AVERAGE NUMBER OF OC- 20 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. s 3 Ss 100 ° i) 2 ° x o o 3 a 3 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) =~ ° o oS 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) |e 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 150 140 6552 OBSERVATIONS 140 || 6552 OBSERVATIONS 16 AVERAGE NUMBER OF OC- 16 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONSEDURINGRINENGEN SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 6 FEET. SON WHEN WAVES ROSE 120 TO 6 FEET OR HIGHER. 100 100 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 140 160 180 200 220 240 260 280 300 120 140 160 180 200 220 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) Fr Ro O 10 20 30 40 50 60 70 80 90 100 37 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 140 6380 OBSERVATIONS 17 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 6 FEET. 110 100 (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 no 100 6380 OBSERVATIONS 17 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 3 SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. SS = 60 Vv Zz a 3 50 = 40 30 20 10 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5D OSV “'D" 44.0°N., 41.0°W. 40 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 no 100 ° oS o °o 70 60 50 > o o ° JULY, AUGUST, SEPTEMBER || 5888 OBSERVATIONS 22 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 300 FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 110 100 5888 OBSERVATIONS 22 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) a NL 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 5824 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES _ DE- CREASED IN HEIGHT BELOW 6 FEET. 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 10 100 5824 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 41 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 6392 OBSERVATIONS 14 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 10 100 6392 OBSERVATIONS 14 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) QO !0 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 6552 OBSERVATIONS 13 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. (?} 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 No 100 6552 OBSERVATIONS 13 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5E OSV “E” 35.0°N., 48.0°W. 42 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 ante) 100 JULY, AUGUST, SEPTEMBER 150 6624 OBSERVATIONS 140 6624 OBSERVATIONS 10 AVERAGE NUMBER OF OC- 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 100 FREQUENCY OF OCCASIONS (PERCENT) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 1) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 390 100 OCTOBER, NOVEMBER, DECEMBER 150 6520 OBSERVATIONS 140 6520 OBSERVATIONS 17 AVERAGE NUMBER OF OC- 17 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 100 FREQUENCY OF OCCASIONS (PERCENT) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 t) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 390 100 43 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 150 140 3608 OBSERVATIONS 140 3608 OBSERVATIONS 22 AVERAGE NUMBER OF OC- 22 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. 10 no = Fa 100 Q 100 4 = 90 w 90 Zz ce) 80 2 80 UV Vv 70 © 70 o (e) 60 > 60 Vv Zz 50 5 50 g & 40 40 30 30 20 20 10 10 0 0 4 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) © 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 150 140 4128 OBSERVATIONS 140 4128 OBSERVATIONS 19 AVERAGE NUMBER OF OC- 19 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 100 100 FREQUENCY OF OCCASIONS (PERCENT) 10) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 ie) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5F OSV ‘“‘H" 36.7°N., 69.6°W. 44 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, 150 140 3680 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 130 120 10 100 AUGUST, SEPTEMBER 150 140 3680 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 130 120 no 100 FREQUENCY OF OCCASIONS (PERCENT) —_ 80 100 120 140 160 180 200 220 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 240 260 280 300 t) 120 140 160 180 200 220 240 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) 260 280 300 [rape ea {o) 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 140 3680 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 130 120 no 100 150 140 3680 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 130 120 10 100 FREQUENCY OF OCCASIONS (PERCENT) 120 140 160 180 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 200 220 240 260 280 300 0 100 120 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) 140 200 220 240 260 280 300 Te cael ea aaaaalruee (0) 10 20 30 40 50 60 70 80 90 100 45 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 110 100 150 140 JANUARY, FEBRUARY, MARCH 150 5760 OBSERVATIONS 140 9 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 120 5760 OBSERVATIONS 9 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE 6 FEET. 110 100 TO 6 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 120 140 160 180 200 220 240 260 280 300 ° 20 40 60 80 DURATION (HOURS) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 130 120 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) i 5824 OBSERVATIONS 140 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 SON WHEN WAVES DE- 110 100 5824 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 6 FEET. 10 100 TO 6 FEET OR HIGHER. FREQUENCY OF OCCASIONS (PERCENT) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) O 10 20 30 40 50 60 70 80 90 100 FIGURE 5G OSV “'I'"’ 59.0°N., 19.0°W. 46 OO Oar 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 150 140 5152 OBSERVATIONS 140 5152 OBSERVATIONS 16 AVERAGE NUMBER OF OC- 16 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 10 & 100 Q 100 & 90 w 90 Z (e} 80 2 80 re) °o 70 Oo 70 ra fe} 60 is 60 Zz 3 50 50 g bra 40 40 30 30 20 20 10 10 ) ° . t) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 (e) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 150 140 +] 5096 OBSERVATIONS 140 5096 OBSERVATIONS | 11AVERAGE NUMBER OF OC- 11 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. 110 no = & 100 Y 100 ES 90 nw 90 Z Q 80 2 80 UV VY 70 oO 70 fo) 60 > 60 z 50 g 50 40 * 40 30 30 20 20 10 10 °> 20° 40 60 80 100 120 140 160 180 200 220 240 260 260 300 a0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 47 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 120 100 150 140 JANUARY, FEBRUARY, MARCH 5760 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. FREQUENCY OF OCCASIONS (PERCENT) 160 180 200 220 240 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) 130 120 10 100 260 280 300 150 140 130 120 10 100 90 5760 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 120 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (5 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 5824 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 6 FEET. 80 100 120 140 160 180 200 220 240 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 260 280 300 150 140 130 120 ante) 100 5824 OBSERVATIONS 15 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 6 FEET OR HIGHER. 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (= O 10 20 30 40 50 60 70 80 90 100 FIGURE 5H OSV “J” 52.5°N., 20.0°W. 48 6, 9, 12 FT.) 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 150 140 5152 OBSERVATIONS 140 5152 OBSERVATIONS 15 AVERAGE NUMBER OF OC- 15 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. ne) _ 110 = Zz a 100 Y 100 & 90 » 90 74 Q 80 2 80 Uv i) 70 ° 70 fo) 60 5 60 Zz 5 50 50 g & 40 40 30 30 20 20 10 10 () 0 L. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (= 6, 9, 12 FT.) Fore A 10 20 30 40 50 60 70 80 390 100 OCTOBER, NOVEMBER, DECEMBER 150 150 140 5096 OBSERVATIONS 140 5096 OBSERVATIONS 8 AVERAGE NUMBER OF OC- 8 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 6 FEET OR HIGHER. 6 FEET. no 110 100 100 90 FREQUENCY OF OCCASIONS (PERCENT) (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE WAVES(< 6, 9, 12 FT.) PERSISTENCE OF UNFAVORABLE WAVES(S 6, 9, 12 FT.) O 10 20 30 40 50 60 70 80 930 100 49 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 150 140 5040 OBSERVATIONS 140 5040 OBSERVATIONS 21AVERAGE NUMBER OF OC- 21 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. 10 110 100 100 FREQUENCY OF OCCASIONS (PERCENT) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) ea O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 300 150 150 140 | | 5096 OBSERVATIONS 140 {| 50%6 OBSERVATIONS 19 AVERAGE NUMBER OF OC- 19 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. ne) — 110 5 Zz & 100 Y 100 = 2) 90 2 90 fe) 80 2 80 Uv Vv 70 ° 70 . fe} 60 5 60 Zz & 50 3 50 £ 40 40 30 30 20 20 10 10 C) 0) 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) brn A O 10 20 30 40 50 60 70 80 90 100 FIGURE 51 OSV “M” 66.0°N., 2.0°E. 50 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 JULY, AUGUST, SEPTEMBER 140 5152 OBSERVATIONS 1 150 100 19 AVERAGE NUMBER OF OC- 9) CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 5 FEET. 10 (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 5152 OBSERVATIONS 19 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. 0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (3=5, 8, 12 FT.) © 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 140 [| 5096 OBSERVATIONS 22 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW no 100 5 FEET. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 +| 5096 OBSERVATIONS 22 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) La O 10 20 30 40 50 60 70 80 90 100 51 LIGHTSHIPS OF THE NORTH SEA AND BALTIC SEA Because of the higher latitude locations of the North and Baltic Seas, the North Atlantic storm tracks influence these sea regions throughout the year. Storm activity here is more frequent and more intense during the autumn and winter seasons. Therefore, a higher number of occasions above and below certain threshold heights are experienced at the North and Baltic Sea lightships in autumn and winter. The spring and summer seasons are controlled largely by the Azores high pressure circulation, which produces long periods of favorable wave conditions. These points are reflected in the persistence curves for the North and Baltic Sea lightships in Figures 7A through 7F Although the autumn and winter storms are of severe intensity, the buildup of waves to higher height categories and unfavorable wave condi- tions is hindered both by the shallow waters of the North and Baltic Seas and by the limitations of their semienclosed and closed basins to fetch distances. The shallow waters retard wave growth (both in height and length) within the basins, and wave shoaling (the alteration of a wave proceeding from deep water into shallow water) reduces much of the energy content of waves through bottom friction and thus shortens wavelengths and steepens wave crests often to the point of breaking far offshore. Shallowest depths are present at Elbe I Lightship in the North Sea. How- ever, the sheltering effect of land on oceanic wave trains headed toward these sea regions and the rapid migration of storms through these regions probably are more responsible for the short durations of unfavorable waves at the selected lightships. Maximum sheltering occurs at the Baltic Sea lightships (Figures 7E and 7F), On occasion, however, when winds of gale force are blowing steadily onshore, water regions of shoaling bottom are plagued by the development of steep crested seas on the far end of fetch areas. The occurrence of this phenomenon on the Danish side of the North Sea during a western gale is notoriously dangerous to small ships, as well as the western part of the English Channel when storm waves are directed from the open Atlantic. Persistence of strong onshore winds over a period of time piles up the water at the far end of the fetch area along the shoreface. When a basin lacks an outlet for sufficient drainage, the result is a storm surge or seiche, Storm surges raise the normal level of the water and permit waves to run farther up the shoreface before breaking. When a strong surge from a meteorological influence occurs in coincidence with the period of high tide, both reaching their peak at the same time, the result is a flooding of the adjacent lowlands and possible damage to breakwaters and seawalls by the tremendous force of pounding breakers. It was this type of situation which brought about the disastrous North Sea storm of February 1953 which inundated over 1,00 square miles in Holland and England, claimed 1,611 lives, left 100,000 people homeless, and caused untold millions of dollars of damage to property and livestock. 52 In general, however, the persistence curves of the North Sea and Baltic Sea lightships (Figures 7A through 7F ) indicate long durations of favorable waves and relatively short durations of unfavorable wave conditions throughout the year. D3 ELBE, |< Pi1/ge \ P15/12¢@ FIGURE 6 LOCATION CHART OF NORTH SEA AND BALTIC LIGHTSHIPS 54 LEGEND AND EXAMPLES PU ee im TT 6552 OBSERVATIONS 6552 OBSERVATIONS WAVES DECREASED IN HEIGHT BELOW] 14-aVERAGE NUMBER OF OC. WAVES ROSE TO 8 FEET OR HIGHER|| 14 ayeRaGe NUMBER OF OC. 8 FEET AND LASTED 4 TO >300 HOURS CRCIGNGNDURINIGEINENSER LASTED 4 TO >300 HOURS CASIGRGEDURINGIEHERSER™ ON 24 OCCASIONS (150% x 16)* SON WHEN WAVES DE- 4 OCCASIONS (150% x 16)** SON WHEN WAVES ROSE DURING THE SEASON. CREASED IN HEIGHT BELOW DURING AIENSEASON: TO 5 FEET OR HIGHER. 5 FEET. WAVES DECREASED IN HEIGHT BELOW 5 FEET AND LASTED 3 TO 144 HOURS ON 16 OCCASIONS (100% x 16) DURING THE SEASON. WAVES ROSE TO 5 FEET OR HIGHER AND LASTED 3 TO >300 HOURS ON 16 OCCASIONS (100% x 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW 5 FEET AND LASTED 10 TO 144 HOURS ON 12 OCCASIONS (75% x 16) DURING THE SEASON. WAVES ROSE TO 5 FEET OR HIGHER AND LASTED 22 TO >300 HOURS ON 12 OCCASIONS (75% xX 16) DURING THE SEASON. WAVES DECREASED IN HEIGHT BELOW 8 FEET AND LASTED 45 TO>300 HOURS ON 8 OCCASIONS (50% Xx 16) DURING THE SEASON. WAVES ROSE TO 8 FEET OR HIGHER AND LASTED 47 TO >300 HOURS ON 8 OCCASIONS (50% xX 16) DURING THE SEASON. = Zz & Uv 2 o = a Z ©) rr) < UV u fe} ne fo} ~ Vv Zz é 2 o Nd & & FREQUENCY OF OCCASIONS (PERCENT) WAVES DECREASED IN HEIGHT BELOW WAVES ROSE TO 12 FEET OR HIGHER 12 FEET AND LASTED 128 TO >300 AND LASTED 46 TO 186 HOURS ON HOURS ON 4 OCCASIONS (25% X 16) 4 OCCASIONS (25% X 16) DURING DURING THE SEASON. THE SEASON. 140 160 180 200 220 240 260 160 180 200 220 240 260 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) * IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES BELOW 5 ** IN THIS EXAMPLE, FOR EACH TWO OCCURRENCES OF WAVES 5 FEET OR FEET THERE ARE THREE CHANCES WAVES WILL BE LESS THAN 8 FEET. HIGHER THERE ARE THREE CHANCES WAVES WILL EQUAL OR EXCEED 8 FEET. LEGEND & WAVE HEIGHT a ro oan \? © 10 20 30 40 50 60 70 80 90 100 SUMMARY SCALE (ALL DIRECTIONS) FIGURE 7 WAVE PERSISTENCE CURVES AND WAVE HEIGHT BAR GRAPHS FOR NORTH SEA AND BALTIC SEA LIGHTSHIPS 55 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 5128 OBSERVATIONS 20 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. i) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 5128 OBSERVATIONS 20 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. 100 to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 5911 OBSERVATIONS 8 AVERAGE NUMBER OF OC- 130) CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 5S FEET. ate) ) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 5911 OBSERVATIONS 8 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. ante) 100 (°) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 FIGURE 7A S-2 54°0.5/N., 3°32.0'E. 56 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 5949 OBSERVATIONS 140 5949 OBSERVATIONS 14 AVERAGE NUMBER OF OC- 14 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. FREQUENCY OF OCCASIONS (PERCENT) 40 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 5872 OBSERVATIONS 140 5872 OBSERVATIONS 29 AVERAGE NUMBER OF OC- 29 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. no 60 FREQUENCY OF OCCASIONS (PERCENT) () 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 57 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 8378 OBSERVATIONS 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. FREQUENCY OF OCCASIONS (PERCENT) 150 140 160 180 200 220 240 260 280 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 300 8378 OBSERVATIONS 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. © 10 20 30 40 50 60 70 80 90 100 9546 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. APRIL, MAY, JUNE 90 80 40 FREQUENCY OF OCCASIONS (PERCENT) 80 100 120 140 160 180 200 220 240 260 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 280 300 150 140 120 140 160 180 200 220 240 260 280 DURATION (HOURS) 130, 120 no 100 PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) 9546 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 300 O 10 20 30 40 50 60 70 80 90 100 FIGURE 7B P-15/12 54°0.0’N., 7°51.0’E. 58 120 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) 140 160 180 200 220 240 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 9636 OBSERVATIONS 18 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 140 9636 OBSERVATIONS 18 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. no 100 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 8903 OBSERVATIONS 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 8903 OBSERVATIONS 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 10 20 30 40 50 60 70 80 930 100 59 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 150 140 JANUARY, FEBRUARY, MARCH 150 130 120 8948 OBSERVATIONS 140 8948 OBSERVATIONS 28 AVERAGE NUMBER OF OC- 28 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. no 100 5 FEET. FREQUENCY OF OCCASIONS (PERCENT) 150 140 (0) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 9322 OBSERVATIONS 140 9322 OBSERVATIONS 11TAVERAGE NUMBER OF OC- 11 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 100 CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. an Te) 100 300 FREQUENCY OF OCCASIONS (PERCENT) L0) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 () 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) fre a 10 20 30 40 50 60 70 80 90 100 FIGURE 7C P-11/8 54°16.0’N., 7°11.5’E. 60 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 150 140 || 9779 OBSERVATIONS 9779 OBSERVATIONS 19 AVERAGE NUMBER OF OC- 19 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW TO 5 FEET OR HIGHER. 5 FEET. 110 100 FREQUENCY OF OCCASIONS (PERCENT) ° 2 () 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 i) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 0 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 150 140 9593 OBSERVATIONS 140 {| 9593 OBSERVATIONS 28 AVERAGE NUMBER OF OC- 28 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. no ante) 100 100 300 FREQUENCY OF OCCASIONS (PERCENT) (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 1°) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 61 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, 150 140 9734 OBSERVATIONS 4 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. 130 120 100 L¢) 20 40 60 80 100 120 140 160 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 180 200 220 240 260 280 300 FEBRUARY, MARCH FREQUENCY OF OCCASIONS (PERCENT) 150 140 9734 OBSERVATIONS 4 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 130 120 no 100 80 100 120 140 160 180 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) 200 220 240 260 280 300 O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 9828 OBSERVATIONS 1 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. 130 120 aT) 80 100 120 140 160 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 180 200 220 240 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) 150 9828 OBSERVATIONS 1 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 40 30 20 80 100 120 140 160 180 200 220 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) 240 260 280 300 O 10 20 30 40 50 60 70 80 90 100 FIGURE 7D ELBE | 54°0.0’N., 8°10.7’E. 62 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) 130 120 no 100 150 140 130 120 aie) 100 JULY, AUGUST, SEPTEMBER 150 9936 OBSERVATIONS 140 9936 OBSERVATIONS 4 AVERAGE NUMBER OF OC- 4 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. 110 100 FREQUENCY OF OCCASIONS (PERCENT) 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) I mee eT 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 150 9912 OBSERVATIONS 140 9912 OBSERVATIONS 6 AVERAGE NUMBER OF OC- 6 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. FREQUENCY OF OCCASIONS (PERCENT) PPO29COn Bosc Kcn. 40 60 80 100 120 140 160 180 200 220 240 260 280 300 (0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) [rae prt appa O 10 20 30 40 50 60 70 80 90 100 63 JANUARY, FEBRUARY, MARCH 150 4682 OBSERVATIONS 140 4682 OBSERVATIONS 20 AVERAGE NUMBER OF OC- 20 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. 110 100 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) = 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 °o 20 «40°«60 «80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 150 140 4908 OBSERVATIONS 140 4908 OBSERVATIONS 9 AVERAGE NUMBER OF OC- 9 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- SON WHEN WAVES ROSE 120 CREASED IN HEIGHT BELOW 120 TO 5 FEET OR HIGHER. 5 FEET. 100 100 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) *o 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 °> 2040 + 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) Ut © 10 20 30 40 50 60 70 80 90 100 FIGURE 7E KIEL 54°29.9/N., 10°18.0°E. 150 140 130 120 0 100 FREQUENCY OF OCCASIONS (PERCENT) JULY, AUGUST, SEPTEMBER 4965 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. 20 40 60 80 100 120 140 150 140 FREQUENCY OF OCCASIONS (PERCENT) 4965 OBSERVATIONS 10 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 160 180 200 220 240 260 280 300 i) 20 40 60 80 100 120 140 160 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 180 200 220 240 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) 260 280 300 FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 no 100 O 10 20 30 40 50 60 70 80 90 100 OCTOBER, NOVEMBER, DECEMBER 4591 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. 180 200 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) 220 240 260 280 | FREQUENCY OF OCCASIONS (PERCENT) 150 140 130 120 110 100 || 4591 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. O 10 20 30 40 50 60 70 80 90 100 65 80 100 120 140 160 180 200 220 240 260 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) 280 300 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) JANUARY, FEBRUARY, MARCH 150 140 4636 OBSERVATIONS 27 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 5 FEET. no 100 0) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 4636 OBSERVATIONS 27 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. no 100 te) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (=5, 8, 12 FT.) O 10 20 30 40 50 60 70 80 90 100 APRIL, MAY, JUNE 150 140 4914 OBSERVATIONS 14 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES DE- 120 CREASED IN HEIGHT BELOW 5 FEET. 110 100 t) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 12 FT.) FREQUENCY OF OCCASIONS (PERCENT) 150 140 4914 OBSERVATIONS 14 AVERAGE NUMBER OF OC- 130 CASIONS DURING THE SEA- SON WHEN WAVES ROSE 120 TO 5 FEET OR HIGHER. Oo to) 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 12 FT.) [oer 10 20 30 40 50 60 70 80 90 100 FIGURE 7F FEHMARNBELT 54°36.0/N., 11°9.0’E. 66 FREQUENCY OF OCCASIONS (PERCENT) FREQUENCY OF OCCASIONS (PERCENT) || 4968 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 5 FEET. JULY, AUGUST, SEPTEMBER FREQUENCY OF OCCASIONS (PERCENT) 140 DURATION (HOURS) 160 180 200 PERSISTENCE OF FAVORABLE SEAS (<5, 8, S FEET. 220 12 FT.) [rm A OCTOBER, NOVEMBER, DECEMBER 4968 OBSERVATIONS 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES DE- CREASED IN HEIGHT BELOW 240 260 280 4968 OBSERVATIONS 19 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 300 i) 20 PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 10 20 30 40 50 60 70 80 90 100 150 140 80 100 2 120 140 160 180 200 220 240 260 280 DURATION (HOURS) 12 FT.) 4968 OBSERVATIONS 27 AVERAGE NUMBER OF OC- CASIONS DURING THE SEA- SON WHEN WAVES ROSE TO 5 FEET OR HIGHER. 300 FREQUENCY OF OCCASIONS (PERCENT) 160 DURATION (HOURS) PERSISTENCE OF FAVORABLE SEAS (<5, 8, 180 200 220 240 260 280 12 FT.) (0) 0 b 300 0 20 10 20 30 40 50 60 70 80 90 100 67 120 DURATION (HOURS) PERSISTENCE OF UNFAVORABLE SEAS (55, 8, 140 160 180 200 220 240 260 280 12 FT.) 300 APPLICATION OF WAVE PERSISTENCE GRAPHICS The wave persistence graphics presented in this report contain a wealth of information when applied to specific problems involving dura- tion of particular wave heights. The graphs are intended for application to any particular operation or problem, where the limits of the operation or problem determine whether the waves are favorable or unfavorable. Several examples of the application of wave persistence are: dh Te forecasting durations of storm waves, which can result in economic savings to maritime concems when known regions of adverse waves of long durations are avoided in ship routing; estimating durations of particular wave height categories which are hazardous to refueling operations or cargo transfer; estimating durations of regional adverse wave conditions which would hinder or restrict survey operations or salvage operations; estimating durations of particular wave heights pertinent to construction of offshore platforms for oil drilling or communications; gaining nearshore information on duration of adverse waves and breakers pertinent to the construction of piers, breakwaters, dikes, and other structures along coastlires or harbors; predicting high water levels and durations from storm surges affecting unprotected coastal installations; predicting extent of beach erosion and shoreline processes by relating sustained wave action with beach profile characteristics. Many more applications of wave persistence are possible, depending on the special requirements of the user. Whatever the interest, it is hoped that this initial investigation of wave persistence will encourage further research on a subject of great concern to all engaged in martime operations and to all affected by wave activity. 68 BIBLIOGRAPHY Bigelow, Henry B. and Edmondson, W. T, Wind waves at sea, breakers and surf. Hydrographic Office Publication No. 602. 177 p. 19h7. Reprinted 19 53 ; Cooperman, A. I. and Rosendal, H. E. Great Atlantic coast storm, 1962, Mariners Weather Log, vol. 6, no. 3, p. 79-85, 1962. Dubach, H. W. and Maloney, W. E. A discussion of the meteorological and oceanographical conditions resulting in the storm disaster in the Trish and North Seas on February 1, 1953, Paper presented at Meeting of the American Geophysical Union, Washington, May 1953. U. S. Naval Oceanographic Office. Oceanographic atlas of the North Atlantic Ocean, section IV, wind, sea, and swell, Washington, D.C. U. S. Weather Bureau and U. S. Hydrographic Office. Climatological and oceanographic atlas for mariners, Vol. I, North Atlantic Ocean. 7 p. and 182 charts. Washington. 1959. U. S. Weather Bureau. Wave data. Tabulated by U. S. Weather Bureau from Weather Bureau Deck 116 (U. S. Merchant Marine Deck, 199 to present). Unpublished. 69 U. S. Naval Oceanographic Office A STUDY OF WAVE PERSISTENCE FOR SELECTED LOCATIONS IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA, by John M, Kipper and Ellis ate September 1963. 7h p. 59 figures (TR- 19). This report presents wave persistence graphs which were constructed from wave data obtained from lightships and ocean station vessels. An explanation and examples of how to interpret the graphics are given, A climatological summary for the selected regions is given to assist in arriving at certain generalizations concerning wave persistence. U. S. Naval Oceanographic Office A STUDY OF WAVE PERSISTENCE FOR SELECTED LOCATIONS IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA, by John M, Kipper and Ellis see September 1963. 7h p. 59 figures (TR- 149). This report presents wave persistence graphs which were constructed from wave data obtained from lightships and ocean station vessels. An explanation and examples of how to interpret the graphics are given, A climatological summary for the selected regions is given to assist in arriving at certain generalizations concerning wave persistence. Io (0 3. Ale Wave Persistence Sea and Swell Ship Routing title: A Study of Wave Persistence for Selected Locations in the North Atlantic Ocean, North Sea, and Baltic Sea authors: John M, Kipper and Ellis Joseph TR-1h9 Wave Persistence Sea and Swell Ship Routing title: A Study of Wave Persistence for Selected Locations in the North Atlantic Ocean, North Sea, and Baltic Sea authors: John M. Kipper and Ellis Joseph TR-1h9 U. S. Naval Oceanographic Office A STUDY OF WAVE PERSISTENCE FOR SELECTED LOCATIONS IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA, by John M. Kipper and Ellis ae September 1963. 7h p. 59 figures (TR- 1h9). This report presents wave persistence graphs which were constructed from wave data obtained from lightships and ocean station vessels. An explanation and examples of how to interpret the graphics are given, A climatological summary for the selected regions is given to assist in arriving at certain generalizations concerning wave persistence. U. S. Naval Oceanographic Office A STUDY OF WAVE PERSISTENCE FOR SELECTED LOCATIONS IN THE NORTH ATLANTIC OCEAN, NORTH SEA, AND BALTIC SEA, by John M. Kipper and Ellis pee: September 1963. 7h p. 59 figures (TR- 1h9). This report presents wave persistence graphs which were constructed from wave data obtained from lightships and ocean station vessels. An explanation and examples of how to interpret the graphics are given, A climatological summary for the selected regions is given to assist in arriving at certain generalizations concerning wave persistence. Wave Persistence Sea and Swell Ship Routing title: A Study of Wave Persistence for Selected Locations in the North Atlantic Ocean, North Sea, and Baltic Sea authors: John M, Kipper and Ellis Joseph TR-1h9 Wave Persistence Sea and Swell Ship Routing title: A Study of Wave Persistence for Selected Locations in the North Atlantic Ocean, North Sea, and Baltic Sea authors: John M. Kipper and Ellis Joseph TR-1L9