SHIPS' LIGHTS AND REGULATIONS 195
(d) A vessel when at anchor shall, at intervals of not more
than 1 minute, ring the bell rapidly for about 5 seconds.
(e) A vessel when towing, a vessel employed in laying or
in picking up a telegraph cable, and a vessel under way,
which is unable to get out of the way of an approaching
vessel through being not under command, or unable
to manoeuvre as required by these Rules shall, instead
of the signals prescribed in sub-divisions (a) and (c) of
this Article, at intervals of not more than two minutes,
SOUND THEEE BLASTS in succession, viz., one prolonged
blast followed by two short blasts. A vessel towed
may give this signal *and she shall not give any other.
Sailing vessels and boats of less than 20 tons gross tonnage
shall not be obliged to give the above-mentioned signals, but if
they do not, they shall make some other efficient sound signal at
intervals of not more than 1 minute.t
Speed of Ships to be Moderate in Fog, etc.
AET. 16,—Every vessel shall, in fog, mist, falling snow or heavy
rain-storms, GO AT A MODERATE SPEED, having careful regard to
the existing circumstances and conditions.
A steam vessel hearing, apparently forward of her beam, the
fog-signal of a vessel, the position of which is not ascertained, shall,
so far as the circumstances of the case admit, STOP HEB ENGINES,
and then NAVIGATE WITH CAUTION until danger of collision is over.
NAVIGATION LIGHTS.
Significance of Lights and Signals in Diagrams 1 to 19.
The minimum range of visibility of white masthead lights is
5 miles, coloured lights 2 miles, anchor and stern lights (white),
1 mile, drift net and seine net fishing boats' lights (white), 3 miles.
/I. ART. 2.—A steam vessel under way, heading towards me,
showing masthead lights, also side-lights
f Dutch steam pilot-vessels, when engaged on their station on pilotage duty in fog, mist,
falling snow or heavy rain-storms are required to make at intervals of 2 minutes at most 1 long
blast with the siren, followed after 1 second by a long blast with the steam whistle, and again
after 1 second by a long blast on the siren. When not engaged on their station on pilotage
duty, they make the same signals as other steamships,