Sound signals — listen and identify

Tap Play to hear a randomly-chosen sound signal from COLREG Rules 34 and 35. Choose what you think it means; the answer reveals on selection. Use this for STCW oral-exam preparation or for keeping rusty knowledge sharp on long passages.

Audio is generated in the browser (low-pitched horn tone). Short blast (•) ≈ 1 s. Prolonged blast (—) ≈ 4–6 s. See the full sound-signals reference for the underlying material.

See also

• · Sound signals reference
• · COLREGs — Rules 32–37 in context.
• · Navigation lights — visual companion.