Fog, anchored or aground, International and Inland
At anchor, 100 meters or more
A vessel at anchor, 100 meters or more in length.
Rapid ringing of the bell, then rapid ringing of the gong
Who sounds it
Vessel at anchor, 100 meters or more. Bell in the forepart, gong in the after part.
How it's sounded
Bell and gong each "rapidly for about 5 seconds". The gong follows "immediately after" the bell; 0.2 seconds is used here.
At intervals of not more than 1 minute.
A short blast is about 1 second. A prolonged blast is 4 to 6 seconds. Clips use 1 and 5 seconds.
Worth remembering
Bell forward, then gong aft. Hearing both tells you the vessel is 100 meters or more.
More in fog, anchored or aground
- At anchor, under 100 metersInternational and Inlandrapid ringing of the bell
- Anchored vessel's warningInternational and Inlandone short blast, then one prolonged blast, then one short blast
- Aground, under 100 metersInternational and Inlandthree bell strokes, then rapid ringing of the bell, then three bell strokes
- Aground, 100 meters or moreInternational and Inlandthree bell strokes, then rapid ringing of the bell, then three bell strokes, then rapid ringing of the gong
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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