CHART—Nautical counterpart of a road map, showing land configuration, water depths, and aids to navigation. CHECK—(1) To slow or ease; to check a line is to pay out just enough line to prevent its parting when under a strain. (2) To investigate or examine something. CHEEK—One of the sides of a block. CHOCK—Deck fitting through which mooring lines are led. CHOW—Feed. CHRONOMETER—An accurate clock used in navigation. CLAMP DOWN—To sprinkle the deck with water and dry it with a swab. CLEAT—A metal casting with two projecting arms to which a line is belayed. COAMING—Bulwark around a hatch opening. COFFERDAM—A void between compartments or tanks of a ship for purposes of insulation. COIL—To lay down a line in circular turns piled loosely on top of one another. COLLISION BULKHEAD—A bulkhead, stronger than normal, located forward to control flooding in the event of a head-on collision. COLORS—(1)  The  national  ensign.  (2)  The ceremony of raising and lowering the ensign. COMBATANT SHIP—A  ship  whose  primary mission is combat. COMPANIONWAY—Deck opening giving access to a ladder (includes the ladder). COMPARTMENT—Interior space (room) in a ship. COMPLETE DECK—Any deck that extends the length of a ship from side to side. CONN—Station, usually on the bridge, from which a ship is controlled; the act of controlling the ship’s movements. COURSE—A ship’s desired direction of travel, not to be confused with heading, which is the direction in which the bow is pointed at any given instant. COVER—(1) To protect. (2) A shelter. (3) Headgear, and the act of donning same. COXSWAIN—Enlisted person in charge of a boat. DARKEN SHIP—To turn off all external lights and close all openings through which lights could be seen from outside the ship. DAVITS—A crane or mechanical arms that project over the side of a ship and are used to lower or hoist a boat in or out of the water. DEAD AHEAD—Directly ahead; a relative bearing of 000. Dead astern is 180 relative. DEAD IN THE WATER—A ship that has stopped and has no way on, or no movement through the water. DECK—Horizontal planking or plating that divides a ship into layers. DECK SEAMANSHIP—The upkeep and operation of all deck equipment. DEEP SIX—To throw something overboard. DIP—The act of lowering a flag partway down the staff as a salute to, or in reply to a salute from, another ship. DISTANCE LINE—A line stretched between two ships engaged in replenishment or transfer operations under way. The line is marked at 20-foot intervals to help the conning officer in maintaining station. DIVISION—(1) A main subdivision of a ship’s crew (1st, E, G, and so forth). (2) An organization made up of two or more ships of the same type. DOCK—Commonly refers to any pier or wharf; but, strictly speaking, it refers only to the space alongside a pier or in drydock. DOG—(1) A lever or bolt and thumbscrews used for securing a watertight door. (2) The act of dividing a 4-hour watch into 2-hour watches. DOG DOWN—To set the dogs on a watertight door. DOG WATCH—The 1600 to 1800 and 1800 to 2000 watches. DOLPHIN—(1) A cluster of piles at the end of a pier. (2) A porpoise. DOUBLE UP—To double mooring lines for extra strength. DRAFT—The vertical distance from the keel to the waterline. DRAFT MARKS—The figures fastened to the stem and stern, the center of which indicates the draft of AI-4