Fog, underway, International
Fishing or restricted, at anchor
At anchor but using the underway signal instead of the bell.
One prolonged blast, then two short blasts
Who sounds it
Vessel fishing at anchor, or restricted in ability to maneuver while carrying out her work at anchor.
How it's sounded
Short blast: about 1 second (Rule 32(b)). Prolonged blast: 4 to 6 seconds (Rule 32(c)); 5 seconds is used here. The rule sets no gap between blasts. 1 second is used here so the blasts stay distinct.
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
These two give the three-blast signal instead of the anchor bell.
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
- Power vessel stoppedInternational and Inlandtwo prolonged blasts
- Vessel being towedInternational and Inlandone prolonged blast, then three short blasts
- Composite unit making wayInternational and Inlandone prolonged blast
- Composite unit stoppedInternational and Inlandtwo prolonged blasts
- 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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