Definition of Underway

Underway means that a boat isn’t at anchor, touching the ground in shallow water, or tied to the shore.

Not to be confused with making way, underway means that the boat isn’t recording any resultant speed. This means that its speed is not greater than the opposing speed of the water.

Underway suggests some modicum of control over the vessel and therefore provides a basis for navigation rules.

boats underway

Vessels that are underway must:

  • Steer clear of vessels that are fishing, under sail, restricted in maneuverability, or without command
  • Show the required masthead lights, sidelights and stern lights
  • Sound one prolonged blast at intervals of two minutes whenever visibility is restricted
  • Sound two prolonged blasts with a 2-second interval every two minutes if stopped

Whether your boat is anchored or underway, make sure you’ve got the ideal navigation lights to keep you and other boat operators safe.

Example of Underway in a Sentence

"With the boat underway, the captain switched on the navigation lights as they idled out of the marina on their way to Key Largo"

Synonyms: in motion

Related Terms for Underway