Rule 35 part c of the International Regulations for Preventing Collisions at Sea (72 COLREGS) states that when in restricted visibility (i.e. fog) a sailing vessel is required to sound one prolonged blast followed by two short blasts on the vessel's whistle, at intervals of not more than two minutes. Please refer to the link below.
Rules of the RoadRule 35Sound 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 blasts.
One prolonged blast followed two short blasts, every two minutes, not to exceed two minutes. Rule 35-Sound Signals in restricted visibility.
A power-driven vessel under way sounds one prolonged blast not less than every two minutes. However if it is less than 12meters in length it is not required to give any signal.
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.
loud
It is the responsibility of the captain of the vessel to ensure that it can be detected when sailing in fog- nowadays this is mostly done by GPS and by the use of radio communication, but the skipper of a sailing vessel in foggy conditions should also use a foghorn of some kind, be it a hand-held horn powered by compressed air, or a more sophisticated electrical or pneumatic type that is installed on the vessel itself. There is no set type of audio signal to alert other mariners that a sailing vessel is in the vicinity- morse code is no longer used and most modern sailors don't understand it, so it would just be a general foghorn note.
its easy sound signal
3 short blasts
None. A vessel underway under normal conditions does not need to make any sound signal.If the vessel ceases to make way it still does not make a sound signal unless special circumstances apply.
The sound signals that it is a sailing vessel underway when you hear one prolonged blast plus two short blasts every two minutes.
The sound signals that it is a sailing vessel underway when you hear one prolonged blast plus two short blasts every two minutes.
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)