Fog, underway, International and Inland
Composite unit stopped
A rigidly connected pusher and pushed vessel, stopped and making no way. It counts as one power-driven vessel.
Two prolonged blasts
Who sounds it
Pushing vessel and vessel pushed ahead, rigidly connected.
How it's sounded
Prolonged blast: 4 to 6 seconds (Rule 32(c)); 5 seconds is used here. "An interval of about 2 seconds between them" (Rule 35(b)).
At intervals of not more than 2 minutes.
A short blast is about 1 second. A prolonged blast is 4 to 6 seconds. Clips use 1 and 5 seconds.
In or near an area of restricted visibility, by day or by night. You don't have to be inside the fog.
Worth remembering
Rigidly connected means power-vessel signals, not the towing signal.
The same sound elsewhere
These use the same pattern, so the rules you’re under and the situation decide what it means.
More in fog, underway
- Power vessel making wayInternational and Inlandone prolonged blast
- Limited vessels, underwayInternationalone prolonged blast, then two short blasts
- Limited vessels, underwayInlandone prolonged blast, then two short blasts
- Fishing or restricted, at anchorInternationalone prolonged blast, then two short blasts
- Fishing or restricted, at anchorInlandone prolonged blast, then two short blasts
- Vessel being towedInternational and Inlandone prolonged blast, then three short blasts
- Composite unit making wayInternational and Inlandone prolonged blast
- Pilot vessel identityInternational and Inlandfour short blasts
Study more
See every sound signal, try the free Rules of the Road practice test, or read who gives way, and how Inland differs.
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