When is a vessel considered "under way"?

Answer: B — When it is not anchored, moored, or aground

A vessel is considered "under way" when it is not anchored, moored, or aground. This definition is important as it indicates the vessel's status in relation to navigating and operating on the water. When a vessel is under way, it is free to maneuver and can respond to navigational demands, including avoiding other vessels or navigating through traffic. In contrast, options such as being anchored, completely docked, or at anchor but maneuverable do not fit the definition of under way. When a vessel is anchored, it is stationary and secured to the seabed, while being completely docked implies that the vessel is tied up at a pier or alongside a dock. Lastly, a vessel that is at anchor but still maneuverable is in a unique situation that may not classify it as under way in the same sense; it is not considered actively navigating in the same manner as a vessel that is not secured in any form. Therefore, the correct understanding of being "under way" revolves around the absence of anchors, mooring, or grounding.