Pitch (Vessel Motion)

Angular vessel motion about a transverse axis, alternately raising and lowering the bow and stern.

Pitch is one of the six rigid-body motions of a vessel and is commonly excited by waves, particularly when their encounter period relates to the vessel’s natural response. Unlike heave, which is vertical translation of the whole vessel, pitch is rotation.

Large pitching can cause slamming, propeller emergence, speed loss, seasickness and high structural or securing loads. Course and speed changes may alter the encounter, but the effect depends on hull, loading, wave direction and period.