🔍 Key Concepts

• Sound signals in or near areas of restricted visibility in the Navigation Rules (COLREGS and Inland Rules) • Specific supplementary fog signals used by vessels at anchor, aground, or engaged in special operations • Distinctive patterns used by pilot vessels, vessels being towed, and fishing vessels

💭 Think About

• First, recall the basic required fog signals for power-driven vessels underway, vessels at anchor, and vessels restricted in their ability to maneuver. How many blasts and of what length are normally used? • Then think about which types of vessels use additional short blasts to distinguish themselves from standard underway or at-anchor signals. • Compare the choices: which type of vessel needs a highly recognizable and distinct pattern so other ships can quickly identify its special role or limitation?

✅ Before You Answer

• Verify in the Navigation Rules which vessel type uses one prolonged followed by four short blasts in or near an area of restricted visibility. • Confirm the standard at-anchor fog signal and any optional bells/gongs to see if that matches this pattern. • Check whether vessels being towed or fishing vessels trawling have their own unique fog sound patterns, and if so, what those patterns are.