In or near an area of restricted visibilityThe term 'restricted visibility' means any condition in which visibility is restricted by fog, mist, falling snow, heavy rainstorms, sandstorms or any other similar causes. , whether by day or night, the signals prescribed in this Rule shall be used as follows:
(a) A power-driven vesselThe term 'power-driven vessel' means any vessel propelled by machinery. making way through the water shall sound at intervals of not more than 2 minutes one prolonged blastThe term 'prolonged blast' means a blast of from four to six seconds's duration. More.
(b) A power-driven vesselThe word 'vessel includes every description of water craft, including non-displacement craft, WIG craft and seaplanes, used or capable of being used as a means of transportation on water'. underwayThe word 'underway' means that a vessel is not at anchor, or made fast to the shore, or aground. 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) A vessel not under commandThe term 'vessel not under command' means a vessel which through some exceptional circumstance is unable to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel. , a vessel restricted in her ability to manoeuvreThe term 'vessel restricted in her ability to manoeuvre' means a vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules and therefore is unable to keep out of the way of another vessel. The term 'vessels restricted in their ability to manoeuvre' shall include but not be limited to; (i) a vessel engaged in laying, servicing or picking up a navigation mark, submarine cable or pipeline; (ii) a vessel engaged in dredging, surveying or underwater operations; (iii) a vessel engaged in replenishment or transferring persons, provisions or cargo while underway; (iv) a vessel engaged in the launching or recovery of aircraft; (v) a vessel engaged in mineclearance operations; (vi) a vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course. , a vessel constrained by her draughtThe term 'vessel constrained by her draught' means a power-driven vessel which because of her draught in relation to the available depth and width of navigable water, is severely restricted in her ability to deviate from the course she is following. , a sailing vesselThe term 'sailing vessel' means any vessel under sail provided that propelling machinery, if fitted, is not being used. , a vessel engaged in fishingThe term 'vessel engaged in fishing' means any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict manoeuvrability. More 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) A vessel 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. A vessel at anchor may in addition sound three blasts in succession, namely one short, one prolonged and one short blastThe term 'short blast' means a blast of about one second's duration. More, to give warning of her position and of the possibility of collision to an approaching vessel.
(h) A vessel aground shall give the bell signal and if required the gone 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 whistleThe 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. More 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) A vessel 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.