What do three long blasts and two short blasts mean?

Answer 1

One prolonged followed by one short is NOT a signal defined by International Regulations for Preventing Collisions at Sea, 1972 (72COLREGS). Unless you are are leaving a dock or berth (one prolonged) then immediately arranging a port to port passage. Unless that is the case there is no such thing as 1 prolonged followed by 1 short.

Answer 2

It means that the vessel is at anchor.

The International Regulations on the Prevention of Collision at Sea (COLREGS)

Rule 35: (g)(f) 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 meters or more in length the bell shall be sounded rapidly for about 5 seconds 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 blast, to give warning of her position and of the possibility of collision to an approaching vessel.

Answer 3

Rules of the Road. Rule 35-International

Sound Signals in Restricted Visibility

(f) 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 meters 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 blast in succession, namely one short, one prolonged, one short, to give warning of her position and of the possibility of collision to an approaching vessel.

*There is no long blast, it is "prolonged" and is 4-6 seconds.

Answer 4

One prolonged and two short blasts is 'D' in Morse signals.

It is a signal to be used in restricted visibility by a vessel not under command[NUC], a vessel restricted in her ability to manoeuvre[RAM], a vessel constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel.

Answer 5

coming in to port

The above answer is incorrect.

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)

Answer 6

a vessel is restricted in maneouverability and is in area of low visibility

The above answer is incorrect.

Two long - one short is a signal made by a vessel in sight of another in a narrow channel or fairway; it indicates her intention to overtake on the starboard side of the overtaken vessel.

Collision Regulations 34(c)(i)

Answer 7

a salute