Maritime Navigation Rules and Vessel Responsibilities Practice Test 2026 - Free International and Inland Regulations Practice Questions

Two diamonds shown in a vertical line are a day shape signaling a dredging operation. That day shape tells you the vessel is restricted in its ability to maneuver, so other vessels must keep well clear and pass at a safe distance. In practice, the recommended passing side is on the dredging vessel’s starboard side to give you the clearest clearance away from the dredging work area. So the vessel identified by two vertical diamonds is the dredge.