are signals of intent. The first two signals must be
answered by the other vessel in sight making the same
signal before the proposed action is taken.
One short blast
I propose a port-to-port passage
Two short blasts
Three short blasts
I am operating stern propulsion
Five or more short
One prolonged blast
I am approaching a blind bend
in the channel or leaving a pier
The bend signal is the only one made blind.
It is answered by the same signal by a ship around
the bend. Then, when in sight, the danger signal, or
a signal of
circumstances. Remember, under International Rules,
whistle signals generally are signals of execution or action;
under Inland Rules they are signals of intent or proposal.
LIGHTS AND SHAPES
Navigation Rules states that all seagoing vessels
must show certain lights from sunset to sunrise, whether
at anchor or under way, and during daylight in
restricted visibility. The basic purpose of these lights is
to warn vessels of the presence of other vessels.
Lights also aid in determining the course and aspect of
vessels under way. In some cases, lights indicate a vessel
which is restricted in its ability to maneuver, either
because of physical characteristics or because of the
activity in which it is engaged. The prescribed shapes
serve the same purpose during the day. (See figure 20.)