🔍 Key Concepts

• Vessel restricted in her ability to maneuver (RAM) – definition and responsibility (Navigation Rules, Rule 3 and Rule 18) • Lights and shapes for RAM vessels – what shapes they actually display day vs night (Navigation Rules, Rule 27) • Sound signals in restricted visibility – which vessel uses two prolonged and one short blast (Navigation Rules, Rule 35)

💭 Think About

• Think about which type of vessel normally sounds two prolonged and one short blast in fog. Is that sound signal used by power-driven vessels underway, by RAM vessels, or by another special class of vessel? • Review the shapes for RAM vessels: do they ever show two diamonds in a vertical line, or is that shape used for a different kind of special vessel? • Consider the responsibilities between a vessel restricted in her ability to maneuver and a vessel engaged in fishing. Under the pecking order in Rule 18, who normally keeps out of the way of whom?

✅ Before You Answer

• Check the exact sound signal for restricted visibility for a vessel restricted in her ability to maneuver in Rule 35 and compare it to power-driven and towing vessels. • Verify in Rule 27 which day shapes apply to RAM vessels and which apply to vessels constrained by draft or towing with long tows. • Confirm in Rule 18 the hierarchy of vessels (NUC, RAM, fishing, sailing, power-driven, seaplane, WIG) and see where RAM stands relative to fishing vessels.