The Main Sail Flotation provides 30 lbs. of buoyancy for the top of the mast in case of a capsize. In the Flying Scot, as long as the boat does not turtle, it will not take on water. Regardless, the boat can never sink, but by using a mainsail flotation you can save yourself the work of having to bail the boat after it has turned turtle. Not to mention it’s much easier to right the boat when she just lays on her side.