Ship motions are defined by the six degrees of freedom that a ship, boat or any other craft can experience.
- Heave
- is the linear vertical (up/down) motion
- Sway
- is the linear lateral (side-to-side) motion
- Surge
- is the linear longitudinal (front/back) motion
- Roll
- is when the vessel rotates about the longitudinal (front/back) axis
- Pitch
- is when the vessel rotates about the transverse (side-to-side) axis
- Yaw
- is when the vessel rotates about the vertical (up-down) axis
