Photo Source: http://www.sailtrain.co.uk/stability/vanishing_stability.htm

    Capsizing occurs when a boat continues to heel (to lean) over to the side until it has reached the "angle of vanishing stability" (sailtrain.co.uk).  Before this point, the buoyancy and gravitational forces create a inertia called the righting or restoring moment (RM). The RM will maintain stability unless the sailboat reaches the angle of vanishing stability.  The angle of vanishing stability is considered where the net torque is in equilibrium.  Anymore wind torque to cause the boat past this angle will result in a capsize (Kimball 83).

T[net]=T[wind]+T[buoyancy]=0
-T[wind]=T[buoyancy]

where T is determined from the distribution of mass in relation to center of mass, angular acceleration, and force from wind/buoyancy. 

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