Underway

Underway refers to vessels not anchored or made fast to the shore (for example, a marina or mooring buoy). The vessel may be moving due to the impact of the tide or windage but not under its own means of propulsion.

When under its own propulsion, a vessel is described as Making Way. This is an important distinction and concept in navigation and maritime law, as vessels making way have different roles and responsibilities to those just underway regards collision avoidance (IRPCS).