🔍 Key Concepts

• Sound and Light Signals – Navigation Rules Part D • Distress signals vs. maneuvering/warning signals • Special bridge sound signals under the Inland Rules

💭 Think About

• Think about where in the Navigation Rules continuous fog whistle use is described: is it in the distress section or elsewhere? • Ask yourself: when a vessel cannot see well in restricted visibility, what kind of sound pattern would help other vessels know its presence and status? • Consider which of these choices has its own very specific, internationally recognized sound or visual signal separate from a continuous fog whistle.

✅ Before You Answer

• Verify in the Navigation Rules – Annex IV what constitutes a distress signal. • Verify what sound signals are prescribed in Rules 34–35 for maneuvering and for vessels in or near areas of restricted visibility. • Check whether bridge-opening signals are handled in the general COLREGS, or in local/inland bridge regulations instead.