Underway is a nautical term for a vessel that is not anchored, aground, or tied to the shore. It indicates the vessel is floating freely, even if drifting or barely moving. Underway is distinct from "making way," which requires movement through the water. It means the vessel is not restricted by land or bottom.

Key Aspects of Being Underway:
Legal Status: When a boat lifts its anchor, lets go of the mooring, or casts off lines, it is "underway" in terms of Navigation Rules.

Motion vs. Position: An underway vessel can be adrift or sailing, with or without the engine running.

Vs. Making Way: If a boat is moving under power, wind, or current, it is making way. If it is floating freely but stopped, it is underway but not making way.

Navigation Rules: Vessels underway must adhere to specific lighting requirements, including masthead lights, side lights, and stern lights.