Secondary stability

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) 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.