Broach (sailing)

A sailboat broaches when its heading suddenly changes towards the wind due to wind/sail interactions for which the rudder cannot compensate. This happens when the aerodynamic force on the rig greatly exceeds the hydrodynamic force on the hull, due to a sudden increase in wind strength or turbulent sea conditions. In small boats and dinghies, broaching can lead to a death roll. In larger boats broaching can lay the mast horizontal, putting both rig and crew at risk. It can be particularly dangerous when racing other boats at close quarters.