Discover

'Initial stability' is the resistance of a boat to a small amount of lateral tilting from its equilibrium position. It is determined by the difference in the volume of water displaced on each side of the boat as it tilts and is relatively independent of hull shape for small angles of tilt.
The wider the boat, the greater the difference in water volume displaced during lateral tilting and the greater the initial stability.
Wide boats such as the jonsboat have a great deal of initial stability and allow the occupants to stand upright to engage in fishing activities.
Very narrow boats such as canoes and kayaks have little initial stability. It is essential to keep the centre of gravity as low as possible in such craft so occupants generally sit down at all times. Flatwater rowing shells, which have length to beam ratios of up to 30:1 are inherently unstable and must be actively balanced by the athletes.
After approximately 10 degrees of lateral tilt hull shape gains importance and secondary stability becomes the dominant consideration in boat stability.