When is a vessel considered "underway"?

A vessel is considered "underway" when it is not grounded, anchored, or attached to shore. This definition is crucial in maritime navigation and safety because it indicates that the vessel is in motion, capable of being navigated, and able to respond to the surrounding navigational situation. Underway status means that the vessel is free to maneuver and is obliged to adhere to the rules governing navigation, such as those established by the COLREGs.

Being "anchored" or "moored to a dock" clearly defines a state of rest and attachment to the seabed or shore, which means the vessel is not free to navigate. Additionally, when a vessel is in dry dock, it is out of the water and cannot be considered underway either. Understanding these distinctions is vital for effective navigation and compliance with maritime regulations.