Rules of the Road
Sound and light signals
Rule 34
Maneuvering and Warning Signals
International (Signals of Action)
(a.) When vessels are in sight of one another, a power driven vessel underway, when maneuvering as authorized or required by these rules, shall indicate that maneuver by the following signals on her whistle.
-One short blast to mean "I AM altering my course to starboard";
-Two short blasts to mean "I AM altering my course to port";
-Three short blasts to mean "I AM operating astern propulsion".
Inland (Signals of intent)
(a) When a power driven vessels are in sight of one another and meeting or crossing at a distance within half a mile of each other, each vessel underway, when maneuvering as authorized or required by these rules:
(i) Shall indicate that maneuver by the following signals on her whistle: one short blast to mean "I intend to leave you on my port side" (turning to starboard.); two short blast to mean "I intend to leave you on my starboard" (turning to port); and three short blasts to mean "I am operating astern propulsion"(This is the ONLY action in Inland)
there is a dangerous situation
Two short horn blast from a vessel means that she is turning port and one short horn blast that she is turning starboard
They intend to pass starboard side to starboard side.
They intend to pass starboard side to starboard side.
They intend to pass starboard side to starboard side.
Rule 34International:" I AM altering my course to port."Inland: " I INTEND to leave you on my starboard side or I AGREE to a starboard to starboard passing or I INTEND to overtake you on your portside."They intend to pass starboard to starboard side.
passing on port side
The sound signal short-long-short is an optional, additional signal made by a vessel at anchor in restricted visibility. The signal may be made by such a vessel in addition to her required sound signal to give warning of her position and of the possibility of collision to an approaching vessel.Collision Regulations 35(g)
Rules of the RoadSound and light signalsRule 34Maneuvering and Warning SignalsInternational (Signals of Action)(a.) When vessels are in sight of one another, a power driven vessel underway, when maneuvering as authorized or required by these rules, shall indicate that maneuver by the following signals on her whistle.-One short blast to mean "I AM altering my course to starboard";-Two short blasts to mean "I AM altering my course to port";-Three short blasts to mean "I AM operating astern propulsion".Inland (Signals of intent)(a) When a power driven vessels are in sight of one another and meeting or crossing at a distance within half a mile of each other, each vessel underway, when maneuvering as authorized or required by these rules:(i) Shall indicate that maneuver by the following signals on her whistle: one short blast to mean "I intend to leave you on my port side" (turning to starboard.); two short blast to mean "I intend to leave you on my starboard" (turning to port); and three short blasts to mean "I am operating astern propulsion"(This is the ONLY action in Inland)
It means a vessel is going to back up.
Vessel operators can alert the lock attendant of their request to transit through the lock by sounding one prolonged blast followed by one short blast
Rules of the Road. Rule 35, Sound Signals in Restricted Visibility. (C) A vessel not under command, a vessel restricted in her ability to maneuver, a vessel constrained by her draft, a sailing vessel, a vessel engaged in fishing, and a vessel engaged in towing or pushing another vessel SHALL, sound at intervals of not more than two minutes three blast in succession, namely one prolonged followed by two short blast.