Quick guide - Basic sound signals Ship boat yacht www.coastalsafety.com

Basic sound signals Ship boat yacht www.coastalsafety.com Basic sound signals for ships, boat and yachts.

Sound signals for the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs)

There are three devices used for sound signalling a gong, a bell and a whistle.

A vessel of 12m or more in length shall be provided with a whistle
A vessel of 20m or more in length shall, in addition, be provided with a bell
A vessel of 100m or more in length shall, in addition, be provided with a gong

The whistle, bell or gong shall comply with the specification in COLREGs 1972 Annex III, although the bell or gong may be replaced by other equipment having the same sound characteristics, provided that manual sounding of the required signals shall always be possible.

Vessels of less than 12m in length are still required to have an efficient means of making sound signals, but they do not need to comply with the technical details for sound signal appliances in Annex III of the COLREGs.

SOUND AND LIGHT SIGNALS Rule 32
Definitions
(a) The word “whistle” means any sound signalling appliance capable of producing the prescribed blasts and which complies with the specifications in Annex III to these Regulations.
(b) The term “short blast” means a blast of about one second’s duration.
(c) The term “prolonged blast” means a blast of from four to six seconds’ duration.
Rule 33

Sound signals in restricted visibility
In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:
(a) Apower-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) Apower-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.
(c) Avessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.
(d) A vessel engaged in fishing, when at anchor, and a vessel restricted in her ability to manoeuvre when carrying out her work at anchor, shall instead of the signals prescribed in paragraph (g) of this Rule sound the signal prescribed in paragraph (c) of this Rule.
(e) A vessel towed or if more than one vessel is towed the last vessel of the tow, if manned, shall at intervals of not more than 2 minutes sound four blasts in succession, namely one prolonged followed by three short blasts. When practicable, this signal shall be made immediately after the signal made by the towing vessel.
(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule.
(g) Avessel at anchor shall at intervals of not more than one minute ring the bell rapidly for about 5 seconds. In a vessel of 100 metres or more in length the bell shall be sounded in the forepart of the vessel and immediately after the ringing of the bell the gong shall be sounded rapidly for about 5 seconds in the after part of the vessel. Avessel at anchor may in addition sound three blasts in succession, namely one short, one prolonged and one short blast, to give warning of her position and of the possibility of collision to an approaching vessel.
(h) Avessel aground shall give the bell signal and if required the gong signal prescribed in paragraph (g) of this Rule and shall, in addition, give three separate and distinct strokes on the bell immediately before and after the rapid ringing of the bell. A vessel aground may in addition sound an appropriate whistle signal.
(i) A vessel of 12 metres or more but less than 20 metres in length shall not be obliged to give the bell signals prescribed in paragraphs (g) and (h) of this Rule. However, if she does not, she shall make some other efficient sound signal at intervals of not more than 2 minutes.
(j) Avessel of less than 12 metres in length shall not be obliged to give the above-mentioned signals but, if she does not, shall make some other efficient sound signal at intervals of not more than 2 minutes.
(k) A pilot vessel when engaged on pilotage duty may in addition to the signals prescribed in paragraphs (a),(b) or (g) of this Rule sound an identity signal consisting of four short blasts.