The intended path is not always the direction the bow points. Course is the direction in which a ship is to be steered or is actually making good over the ground, expressed in degrees.

Course to steer accounts for wind, current, and compass error so that the track over the ground matches the planned route. Course over ground is read from GPS or other positioning systems. Navigators distinguish heading (where the bow points) from course (where the ship is going).

In confined waters or heavy traffic, frequent course changes keep the ship on the planned track and clear of dangers. Course alterations are recorded in the log and, when required, signaled to other vessels. Accurate course monitoring is basic to safe navigation.

• Intended or actual path of the ship over the water
• Expressed in degrees from north
• Distinct from heading
• Adjusted for wind, current, and traffic