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. C O L O R S —(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