Rules of the Road · Maneuvering & Warning Signals
Rule 34(b) allows the maneuvering signals to be supplemented by light signals. What does one flash of the light signal mean?
- AI am altering my course to port
- BMy engines are going astern
- CI am altering my course to starboard✓ Correct
- DI am in doubt of your intentions
Explanation
Rule 34(b) mirrors the whistle signals: one flash = altering to starboard, two flashes = altering to port, three flashes = astern propulsion. Each flash lasts about one second with a one-second interval; the sequence repeats at intervals of not less than 10 seconds.
Authority: 72 COLREGS Rule 34(b)
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