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 amoperating astern propulsion"(This is the ONLY action in Inland)
Read more: What_do_two_short_horn_blasts_from_another_vessel_mean_in_a_meeting_situation
They are indicating a dangerous situation exists
They intend to pass starboard side to starboard side.
Means it's about to turn to port.
Pilot vessel engaged in pilotage duties
They are indicating dangerous
Five short horn blasts from another boat on the water usually means danger. It could mean they have doubt in the message they had received from you, whether they did not hear it or did not understand. It can also be used to signal that the boat driver is confused about who has the right away. It is a signal to alert another vessel that you are unsure of its intentions, or doubt whether you are taking enough action to avoid a collision.
NASBLA Standard: 2.1 Resource: Federal Requirements and Safety Tips p.11 Course Location: p. 5Which of the following is a feature of a Type IV PFD?
Six blasts of a ship's horn does not seem to have a meaning. Five blasts will mean that you are possibly too close to another ship.
there is a dangerous situation
they are indicating a dangerous situation exist
Well, honey, three long blasts followed by two short blasts from a Great Lakes ship means they're backing up, just like your ex trying to come back into your life after they realize they messed up. So, keep your distance and let that ship do its thing before it ends up in hot water.
From the USCG Navigational Rules of the Road (International and Inland.)Rule 34Maneuvering and Warning Signals(d) When vessels in sight of one another are approaching each other and from any cause one fails to understand the intentions or actions of another, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least 5 short and rapid blasts of the ships whistle.