Distress, International and Inland

Distress: SOS

A vessel in distress and needing help.

SOS in Morse code

Press play. One signal at a time.

Distress: SOSInternational and Inland
A vessel in distress and needing help.
Annex IV para. 1(d); 33 CFR 87.01(d)

Who sounds it

A vessel in distress.

How it's sounded

The rule gives the Morse group but no timing, and Rule 32 blast lengths don't apply to it. This clip uses the usual Morse 1 to 3 ratio: 0.5 and 1.5 seconds.

A short blast is about 1 second. A prolonged blast is 4 to 6 seconds. Clips use 1 and 5 seconds.

Worth remembering

Three short, three long, three short, by any signaling method.

Study more

See every sound signal, try the free Rules of the Road practice test, or read who gives way, and how Inland differs.

Learn the whole set

Helm drills every signal with flashcards and spaced review, on the web and iPhone.

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Sources

Annex IV para. 1(d); 33 CFR 87.01(d)

Helm is an independent study aid, not affiliated with or endorsed by the U.S. Coast Guard or the National Maritime Center. This page is for study, not navigation guidance or legal advice. Check the current rules before you rely on anything here.