Two long blasts in the fog
Fog signal identification. Developing level, about 2 min. COLREGs Rule 35(a) & (b).
The situation
Fog, visibility about 250 m. Somewhere ahead a vessel is sounding a fog signal at regular intervals. Play it and identify what she is telling you.
What does this fog signal mean?
- A power-driven vessel underway but stopped: Two prolonged blasts, about two seconds apart.
- A power-driven vessel making way: One prolonged blast.
- A vessel restricted in her manoeuvring: One prolonged followed by two short blasts.
Lookout: Count the blasts and judge their length. A prolonged blast lasts four to six seconds; a short one about one second.
The sound answer
A power-driven vessel underway but stopped
Rule 35(b): a power-driven vessel underway but stopped and making no way through the water sounds two prolonged blasts in succession with about two seconds between them, at intervals of not more than two minutes.
Why the other options fall short
A power-driven vessel making way
A power-driven vessel making way sounds one prolonged blast at intervals of not more than two minutes. This signal had two.
A vessel restricted in her manoeuvring
One prolonged followed by two short is the signal of vessels such as those not under command, restricted, constrained, sailing or fishing. No short blasts were sounded here.
Rule 35(a) & (b) · Power-driven vessels in fog
Making way: one prolonged blast at intervals of not more than two minutes. Underway but stopped: two prolonged blasts about two seconds apart, at the same interval.