Yaw is a ship’s rotational motion around its vertical axis — the bow swinging left or right relative to the intended course, essentially the ship’s heading changing.
Yaw and Steering
Controlling yaw is what steering actually does — the rudder generates a turning force that either corrects unwanted yaw (keeping the ship on its intended course) or deliberately induces yaw (to change course). Every course correction, whether made manually by a helmsman or automatically by an autopilot, is a response to yaw.
What Causes Unwanted Yaw
- Wind and current — pushing unevenly against different parts of the hull, particularly with the wind or current from an angle
- Wave action — especially in following or quartering seas, where waves can push the stern sideways and induce yaw
- Following sea steering difficulty — in certain sea states, particularly steep following seas, yaw can become difficult to control and, in serious cases, contribute to broaching (an uncontrolled, dangerous turn)
Autopilot and Yaw Control
Modern autopilot systems continuously monitor heading (via gyro compass) and automatically apply rudder corrections to counteract yaw and maintain the set course — a genuine, continuous control task that used to require constant manual helmsman attention.
Yaw vs Roll vs Pitch
- Yaw — rotation around the vertical axis (heading change)
- Roll — rotation around the longitudinal axis (side to side)
- Pitch — rotation around the transverse axis (bow/stern up and down)
Together with heave, surge, and sway, these six motions describe a ship’s complete motion at sea.
Exam Relevance
Yaw, its causes, and steering/autopilot control of yaw are core Ship Handling and Navigation topics in deck officer competency exams.