Originally Posted by stubones99
it's called angular momentum, i think.
the distance from the center makes it slow down the frequency of rocking, even though the mass of the mast isn't large, it's length is and rocking from one side to another means having to stop the sideways motion of the mast and reverse it in the opposite direction.
What I heard, is the mast is useful in when the sea is coming at the boat from the stern. The wind leans the boat over with the sail, and tends to hold it there keeping it from rolling with the waves.