662 NICHOLLS'S SEAMANSHIP AND NAUTICAL KNOWLEDGE
vi) The first signal-letter hoist indicates that the signal is addressed
to ship Orotavo.
(11) Means "Your boat should keep to leeward until picked up.'*
(iii) The second signal-letter hoist indicates that the message ,«*
from ship Orsova instructing Orotavo what to do.
14. How is a geographical signal distinguished?
It is a four-flag hoist with letter A on top.
15. Are there any pther special four-flag signals?
Yes; ship signal-letters are always four-flag hoists, the top flag
and, in some cases the top two flags, of which indicate the nationality
of the vessel. Thus letter G or M on top indicates a British vessel.
16. What is a substitute and what is it for?
A substitute is a triangular flag. There are three substitutes, 1st,
2nd and 3rd. They are used when a letter is repeated in a group,
thus, A A B B would appear when hoisted as A 1st substitute, B 3rd
substitute.
17. How is a numeral signal made?
By means of the numeral pendants, simply by bending them together
in the order to make up the number, introducing substitutes when
double figures appear in the groups.
18. How are position signals in latitude and longitude distinguished?
The top flag is P, followed by the numeral pendants giving the
latitude and longitude.
19. How are time signals recognised?
The top flag is T, followed by numeral pendants giving the time
in hours and minutes as per the four-figure notation.
20. If you are signalling the exact time by flags, or Morse, how is the
exact instant transmitted to the other vessel?
An even minute is chosen and the hoist intimating the hours and
this minute is hoisted a few minutes in advance* The signalman, as
the time approaches, is on the alert to haul down the flags sharply
whenever a timekeeper stationed at clock or chronometer calls out to
him to do so. The moment of lowering the hoist sharply i$ the exact
minute. The same system is adopted when morsing an even minute ^f