How many blasts to overtake on the port side?
Two prolonged blasts then two short: 'I intend to overtake you on your port side' (Rule 34(c)).
These signals are for a narrow channel or fairway, in sight of each other, when the vessel ahead has to move over to let you pass (Rule 9(e)). The overtaking vessel still keeps out of the way (Rule 13).
- Starboard side: two prolonged and one short.
- Agreement from the vessel ahead: prolonged, short, prolonged, short (Morse C).
- Not happy? At least five short and rapid blasts.
- Short blast about 1 second; prolonged 4 to 6 seconds.
- US Inland Rules use different signals, so many search results don't match the International Rules.
Source: COLREGS Rules 9(e), 13, 32 and 34(c), (d).
Test yourself
Rule 34Question 1 of 5
What does one short blast mean when manoeuvring in sight of one another?
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