Underway

A vessel that is not at anchor, made fast to the shore, or aground, and is actively moving through the water.

In maritime terminology, “underway” is a concept that distinguishes a vessel’s operational status. A ship is considered “underway” when it is not anchored, moored, or grounded, meaning it is free to move and is either being propelled by its engines, sails, or drifting with the current. The term is often used to describe the vessel’s active state, regardless of whether it is moving forward, backward, or even drifting without propulsion. 

Being underway has significant legal and navigational implications. For example, vessels underway must adhere to specific rules of the road (or “COLREGs” – International Regulations for Preventing Collisions at Sea), which dictate how vessels should behave to avoid collisions. These rules include maintaining proper lookout, safe speed, and giving way to other vessels under certain conditions. Additionally, the responsibilities of the crew change when a vessel is underway, as they must be more vigilant in monitoring the ship’s course, speed, and surroundings.

It’s important to note that a vessel can be underway even if it is not making headway (i.e., moving forward), as long as it is not secured to a fixed object or the seabed. The term is also used to differentiate from when a vessel is “making way,” which specifically refers to a ship moving through the water under its own propulsion.