. "auxiliary sails" . "square sails" . "top hamper" . . "sail-making" . "sailing vessel" . "rigid wing sails" . . . "History of sails" . "sail-assisted" . "sail booms" . "ship sails" . . "rigid wing sail" . "sails" . . . "Black sail" . . . . "sailing" . "Sail trim" . . . . . "Sail Area" . . . "foot of the sail" . . . "sailarea" . . "sail lofts" . . . "Sail" . "canvas" . "regular" . . . . "sail design and manufacture" . . . "rigid wing-sail" . "rigid sail" . "sail area" . "sail" . "Sail" .