Which term is NOT defined in Inland Navigation Rules?

• A. Vessel Constrained By Her Draft
• B. Vessel Not Under Command
• C. Vessel Not Under Way
• D. Vessel At Anchor

Answer: (A)

Inland Navigation Rules define specific vessel statuses that carry precise obligations for maneuvering and collision avoidance. Terms like Not Under Command, Not Under Way, and At Anchor are included because they describe situations that affect how other vessels should respond and what signals or lights apply. The term Vessel Constrained By Her Draft is a COLREGS term used to describe a vessel limited by its draft in constrained waters, but it is not defined in the Inland Navigation Rules. Since it lacks a formal Inland definition, you wouldn’t apply Inland-specific rules to it in the same way you would for Not Under Command, Not Under Way, or At Anchor. The other terms listed are indeed defined in Inland Rules, providing clear meanings that guide right-of-way and collision avoidance.