Secondary stability, also known as reserve stability, is a boat or ship's ability to right itself at large angles of heel (lateral tilt), as opposed to primary or initial stability, the boat's tendency to stay laterally upright when tilted to low (<10°) angles.
A greater lateral width (beam (nautical), beam) and more initial stability decrease the secondary stability- once tilted more than a certain angle the boat is conversely harder to restore to its stable upright position.
Other types of ship stability
* Primary stability
* Tertiary stability: For kayak rolling, tertiary stability, or the stability of an upside-down kayak, is also important (lower tertiary stability makes rolling up easier)
* Ship stability
* Kayak#Types of stability