About Sound Signals

A whistle sounds out of the fog — count the short and prolonged blasts and identify the COLREGS manoeuvring signal or fog signal before time expires. Covers COLREGS Rules 34 and 35 completely: manoeuvring and warning signals when vessels are in sight of one another, and sound signals for every vessel type in or near restricted visibility. Every pattern is tested: the five-or-more short blasts doubt signal, fog signals for vessels at anchor, vessels aground, and vessels not-under-command.

Sound signals are one of the most tested COLREGS topics on the USCG examination — eight to twelve questions per sitting. They are also the most time-pressured skill in a real close-quarters situation, when the correct response must come immediately.

• Rule 34: manoeuvring signals — one short (starboard), two short (port), three short (astern)
• Rule 34(d): five or more short and rapid blasts — the doubt/danger signal
• Rule 35: fog signals by vessel type, status, and whether under way or at anchor
• Vessels restricted in ability to manoeuvre vs. vessels constrained by draft in fog