ensign—The flag carried by a ship as the insignia of her nationality. Also, the lowest commissioned officer of the United States Navy.
fathom—A nautical measure, equal to six feet.
fid—A bolt of wood or metal which holds the heel of a topmast.
fife rail—A plank or rail in which a group of belaying pins is kept.
figure of eight—A knot. For illustration see page [193].
flagship—That ship of a fleet or squadron which flies the flag of the admiral in command.
fore and aft—An expression signifying those sails which, when at rest, lie in a line running from bow to stern of a vessel. The sails of a schooner are fore and aft.
forecastle—Formerly a raised “castle” built at the bows of ancient and mediæval ships from which the decks of enemy ships could be attacked. Nowadays the quarters of the crew on board ship—generally in the bows of ships.
foremast—The mast nearest the bow of a vessel having more than one mast, except on yawls, ketches, and other sailboats where the mast nearest the bow is larger than the mast farther astern.
foresail—On a square-rigged ship, the lowest square sail on the foremast. On a schooner, the sail stretched between the boom and the gaff on the foremast.