Sentence:  It is not only of great service in keeping the boat in her due position on the sea, but also in creating a tendency immediately to recover from any sudden <WSD>cant</WSD>, or lurch, from a heavy wave; and it is besides beneficial in diminishing the violence of beating against the sides of the vessel which she may go to relieve. 
Meaning of the word marked with <WSD> tags:  A movement or throw that overturns something.