To Cast Off.—To untie, to allow to go free; viz., "Cast off the main-sheet!" "Cast off that boat's painter!"
Casting.—To pay a yacht off on the desired tack when weighing the anchor, by arranging the sails so as to be taken aback.
Cat Boat-Rig.—A yacht rigged with one mast placed chock forward in the eyes, and without stays or bowsprit, and fitted with one fore-and-aft sail.
Cat's-Paw.—A light breeze or puff of air seen upon the water.
To Calk.—To drive oakum or cotton into the seams to prevent leaking, and to "pay" the same with pitch or tar.
Centre-Board.—A movable keel that can be lowered or hoisted at pleasure.
To Claw off.—To beat to windward from off a lee-shore.
Cleat.—A piece of wood with two horns, fastened to the side of the yacht or to the mast, upon which ropes are made fast.
Clews.—The corners of sails.
Close-Hauled.—To sail as near the wind as possible.