Naval Terminology
This glossary lists many of the specialized words used aboard Navy ships. It includes technical terms and nautical slang, plus everyday words with shipboard origins. The words were compiled from online sources, from publications such as The Bluejacket's Manual, and from contributions of many individuals. You can go quickly to any letter by clicking it in the alphabet at the top of the page.
The section for each letter is headed by the letter's international phonetic form, followed by its international signal flag, its U.S. Navy semaphore representation, and its representation in Morse code. The letter's pre-1957 phonetic form is shown at the end of the line. Click Here to see an overview of all these naval alphabets.
Please help us improve this list of Navy words; we want it to be the best such list in the world. Click Here to submit your additions and corrections. (Don't worry if you don't have a good definition—tell us the word and its meaning in your own words, and we will do the rest.) We are particularly looking for slang and other terms that wouldn't necessarily be found in official publications.
WARNING! Seafaring men have long had a colorful or "salty" manner of speech, filled with sexual, excretory, and other "purple" words not used in polite society. That may be changing in these politically correct times, but to Bowdlerize the language used here would be to deny its rich history. The traditions and origins of "swearing like a sailor" remain. While we have attempted to present things with a bit of humor, if you are easily offended this listing may not be for you. You have been warned.
To help you avoid the saltiest, most purple words, (or to help you find them more easily), they are shown below like this.
 
0 - 9   Numerals
01 level - the deck above the main deck. The next higher decks are the 02 level, the 03 level, and so on. Though these are formally called decks, they are usually referred to as levels, since they are not usually complete decks that run from stem to stern and all the way athwartships.
1MC - the basic public address system on a ship. Reaches all spaces, and is used for general announcements and to transmit general alarm system signals. Control stations are located on the bridge and quarterdeck, and at the central station. Other transmitters may be installed at additional points.
4.0 - a perfect score; used on written tests, examinations, inspections, etc. Pronounced "four-oh."
10% - the number who never get the word. See pass the word.
72 - a three-day liberty, such as over a holiday weekend; named for the number of hours in three days. It is unusual for 72's to be granted, because a man usually has the duty every third day, and cannot be on liberty at that time.
90-day wonder - derisive term for a graduate of OCS. The derision arises from the lack of experience and naval knowledge of the typical graduate. Sometimes seen as 90-day blunder.
 
A    Alfa (AL-fah)
di-dah
formerly Able
Abaft - farther aft of a given point on a ship, as in "abaft the beam," which is said of something which bears between the beam and the stern, or is further back than the ship's middle.  
ABC warfare - Atomic/Biological/Chemical Warfare. In different eras, has been known as NBC warfare (Nuclear/Biological/Chemical) and CBR warfare (Chemical/ Biological/ Radiological).
Abandon ship - get away from the ship, as in an emergency.
Abeam - at right angles to the centerline of, and outside of, the ship. An object that is abeam of your ship is directly off to its side.
Aboard - on or in a ship or naval station.
Abreast - abeam of; directly alongside.
Accommodation ladder - a portable flight of steps down a ship's side, used to get from the deck to the pier, wharf, or water level.
Acey-deucey - a board game traditionally played in off-duty hours; the game is a variety of backgammon.
Acey-Deucey Club - a social club for First- and Second-Class Petty Officers.
Adrift - not secured; scattered about; not properly stowed, or out of place. Gear adrift refers to miscellaneous articles scattered about.
Advance and Transfer - two separate terms involving a ship's turn. Advance is the forward progress made between the time that the rudder is put over and the time the ship is steady on her new course. Transfer is the horizontal displacement of the ship during the same period of time. Advance is maximized in a turn of 90º or more; transfer is maximized in a turn of 180º or more.
Affirmative - Navy term for "yes." The opposite is negative.
Aft - in, near, or toward the stern; not as specific as abaft. Opposite of forward.
After - refers to something aft, particularly when it is the furthest aft thing of its kind. On land, the back room is a room far at the back of the house. Aboard ship, an after compartment is a compartment far toward the stern.
Afternoon watch - the 1200-1600 watch.
Aground - resting on or touching the bottom. If his ship goes aground and is not an amphibious ship designed to do so, it is very bad news for the Captain.
Ahoy - term used to hail a boat or a ship, as in "Boat ahoy!"
Air bedding - an evolution where all hands bring their mattresses, pillows, etc. topside to expose them to the purifying effects of the air.
Airdale, airedale - naval aviator, aka brownshoe. Can also refer to any member of the aviation community, officer or enlisted. Often modified by non-aviation types with the universal adjective.
A. J. Squared-Away - mythical sailor who always has his act together.
Alee - to the leeward side; downwind.
Alfa Mike Foxtrot - see AMF, below.
All hands - the entire ship's company, both officers and enlisted. As in "all hands man your battle stations," etc.
All night in - having no night watches, and therefore able to sleep all night.
Allotment - assignment of a man's pay directly to a person, bank, or other agency. Paid by check, and used to assure payment, no matter where the man may be on payday; commonly used to provide for one's family, to make payments on a debt, etc.
All stop - an order to the engine room to bring all engines, (even if there is only one), to a condition where they are not driving the ship ahead or astern.
Aloft - above the ship's uppermost solid structure; overhead or high above, often on a mast.
Alongside - by the side of the ship or a shore structure.
AMF - acronym for "Adios, Motherfucker," a common farewell phrase. The polite form, "Adios, My Friend," is seldom used among seafarers.
Amidships - in or towards the middle of a ship in regard to length or breadth; rudder amidships means that the rudder is in its center position, aligned with the ship's centerline.
Anchor - a heavy iron device which is attached to a ship by a cable (rope or, usually, chain), and which, being cast overboard, lays hold of the earth by a fluke or hook and thus retains the ship in a particular station.
Anchorage - suitable place for the ship to anchor. Area of a port or harbor set aside for such a purpose.
Anchor ball - black shape hoisted in the forepart of a ship to show that the ship is anchored.
Anchor buoy - small buoy secured by a light line to the anchor, to indicate its position on the bottom.
Anchor cable - chain, wire, or line running between the anchor and the ship.
Anchor detail - the group of men assigned to handle ground tackle when the ship is anchoring or getting underway.
Anchor lights - the riding lights required to be carried by vessels at anchor.
Anchor man - the lowest-graded man in a Naval Academy graduating class, or in any Navy training class.
Anchor pool - the betting pool on the hour and minute the ship will drop anchor or tie up.
Anchor's aweigh - when a ship raises anchor, the anchor is said to be aweigh as soon as it is no longer in contact with the sea bottom. In the process of weighing anchor, the sequence of reports is usually as follows:
"Anchor's at short stay" - The ship has been pulled up to the anchor, but the anchor is still lying on the bottom, undisturbed.
"Anchor's up and down" - The anchor's flukes have broken free of the bottom, and the shank is more or less vertical. The crown of the anchor is still resting on the bottom.
"Anchor's aweigh" - The anchor has left the bottom. At this point the ship is underway, whether or not it is moving through the water under its own power.
Anchor watch - detail of men standing by as a readiness precaution while the ship is at anchor or in port.
Anemometer - instrument to measure wind velocity.
Antifouling paint - composition applied to reduce marine growths on a ship's bottom.
APC - aspirin-like headache remedy, no longer in use. Familiarly called "All Purpose Capsules," they took their name from their ingredients: aspirin, phenacetin and caffeine.
Armament - the weapons of a ship or aircraft.
ASAP - As Soon As Possible. Usually spoken as a word, "A-sap," with the first "A" accented and given the long sound.
Ashore - on the beach or shore.
Astern - behind, or toward the stern; said of an object or vessel that is abaft another vessel or object.
Athwart or athwartships - across; at right angles to the fore and aft centerline of the ship or other object.
Augment - to transfer from the Naval Reserve to the regular Navy. "LTJG Savio wanted to make the Navy his career, so he put in his papers to augment."
Auxiliary - an assisting machine (such as an air conditioner) or vessel (such as an ammunition ship).
Avast - a command to cease or desist from whatever is being done. "Avast heaving on that line, Berninger."
Awash - so low in the water that water is constantly washing across the surface.
Away all Boats - the command to launch all an amphibious ship's boats. Also the title of a famous book and movie about amphibious operations.
Aweigh - see anchor's aweigh, above.
AWOL - Absent WithOut Leave; an offense under Article 86 of the UCMJ. It is pronounced "A-woll," with the "A" being long and accented.
AWOL bag - small canvas or vinyl bag used to carry clothing or personal items while on weekend liberty.
Aye, aye - reply to an order or command, indicating that it is understood and will be carried out.
Azimuth - the bearing of an object from the observer, measured as an angle clockwise from true north or the heading of the ship.
 
B    Bravo (BRAH-voh)
dah-di-di-dit
formerly Baker
Backing - operating the ship's engine(s) so that they tend to drive the ship astern. Used primarily in slowing or stopping a ship, and occasionally to make it go backwards.
Backing down - same as backing, above.
Bad shit - a situation, or a collection of material, etc. that is especially not good. "Bringing drugs aboard can lead to some very bad shit."
Bag - to get, or collect. "I'm going to go below and bag some Z's." Also to abandon, or leave. "Let's bag this gin mill and get back to the ship."
Ballast - heavy weights packed in the bottom of a ship to give her stability.
Ballast tanks - double bottoms for carrying water ballast and capable of being flooded or pumped out at will.
Balls to the wall - maximum speed, or maximum effort.
Bandit - air contact positively identified as hostile. A bogey is an unidentified air contact.
Barge - any boat reserved for use by an Admiral. Also an unpowered flat-bottomed craft used to haul material.
Barnacles - small shellfish that attach themselves to submerged structures, including a vessel's undersides.
Batten down - to cover and make fast, secure, or shut; usually said of a watertight fixture or structure. Originally, deck hatches did not have hinged, attached covers. Hatch covers were separate pieces which were laid over the hatch opening, then made fast with battens (pieces of timber).
Battle cover - the steel cover for a port or deadlight.
Battle lantern - A rugged battery-powered lantern for emergency use.
Battle lights - dim red lights that furnish sufficient light for personnel during darken ship.
Beach - ashore, or to be put ashore. "The Navigator ran us aground and they beached him."
Beach Jumper - member of an extremely secret Naval Special Warfare unit, founded in WWII by Douglas Fairbanks, Jr., and disbanded in the 1970s.
Beachmaster - the officer in charge of the beach in an amphibious landing. He and his beach party control everything between the surf and the high water line, and are responsible for the proper handling of all men and cargo as they come ashore from the sea.
 Beam - the greatest athwartships width of a vessel, usually found about halfway between the bow and the stern. Also, an object directly to port (or starboard) is said to bear on the port (or starboard) beam.
Bear a hand - speed up the action; lend a helping hand. "Now bear a hand in rigging the ship for heavy weather."
Bearing - the direction of an object, expressed in degrees clockwise from zero, either as relative or true bearing. Relative bearings are measured from the bow of the ship; true bearings are measured from true north.
Before the mast - from the days of sail; literally, the position of the crew whose living quarters on board were in the forecastle (the section of a ship forward of the foremast). The term is also used more generally to describe seamen as compared with officers, in phrases such as "he sailed before the mast."
Belay - to stop. "Belay the chatter on the bridge." Also, an instruction to disregard a request or an order, as in "belay my request for overnight liberty." Finally, to secure a line to a fixed point.
Belaying pin - a wooden or iron pin fitting into a rail upon which to secure lines.
Bells - bells are traditionally rung every half hour during a watch. One bell is rung after the first half hour, two after the first hour, and so on to eight bells, rung at the end of the four-hour watch. Bells are rung in sequenced pairs, so five bells would be sounded ding-ding, ding-ding, ding.
Below - within the ship, but beneath the main deck. To go below is to go below decks.
Below decks - any place below the main deck.
Benny - a treat or reward, derived from benefit.
Benny Sugg - a Beneficial Suggestion program where personnel were rewarded for making suggestions to improve some aspect of military life, usually living conditions.
BEQ - Bachelor Enlisted Quarters; apartments and barracks ashore, reserved for enlisted personnel without families.
Berth - space assigned a vessel for anchoring or mooring. Also, a man's bunk.
Bight - a loop in or a slack part of a line. Also a curve or bend in a shoreline, or a small body of water formed by same.
Bilge - the area below the deck gratings in the lowest spaces of the ship, where things, especially liquids, tend to collect. Also, to fail an examination. "Dingle bilged his test for Machinist's Mate Third Class."
Bilge rat - someone who works in the engineering spaces; a snipe.
Billet - a  specific position in the ship's organization. For example, First Division Officer, Captain's yeoman, etc. Also, the position to which one is assigned. "Mr. Sander's billet was Electronics Material Officer."
Binnacle - a large stand used to house a magnetic compass and its fittings; typically found next to or in front of the ship's wheel.
Binnacle list - sick list; a listing of the names of the men currently in sick bay and unable to perform their duties due to sickness or injury. This list was originally to be found attached to the binnacle.
Bitchbox - an amplified intercom, such as the 1MC, used to communicate between spaces of the ship.
Bitter end - the free or loose end of a line. Originally, the bitter end of a mooring line was taken to the bitts to secure it.
Bitts - mooring fixtures on the deck of a ship. Their counterparts ashore are bollards.
Black-Hand Gang - the engine room and fire room crew. Older (ca. WW II), less politically-correct form is Black Gang. Originally, it referred to the appearance of men who had been handling or working around coal. During WWII, members of the Black Gang were issued black hats instead of white ones, and were therefore sometimes called black hats.
Blackshoe - member of the surface or submarine community. Until recently, the only approved footwear for these communities was black in color. More recently, brown footwear is optional, but seldom seen due to tradition. A brownshoe is a member of the Naval aviation community, where brown shoes have been worn for many years.
Blivet - traditionally, "ten pounds of shit in a five-pound bag." Technically, a rubber fuel bladder.
Block - an apparatus consisting of an outside shell and a sheave or pulley through which a line may be passed.
Blow tubes - in ships with oil-fired boilers, an operation performed several times daily to clean the soot from tubes internal to the boiler. The operation generates significant amounts of soot and smelly gases, and often requires the ship to sail abreast of the wind, so these will not foul the weather decks.
Bluejacket - a Navy enlisted man below the grade of Chief Petty Officer; bluejackets are the typical "sailor," wearing the traditional sailor's uniform, with white hat, blue or white jumper, black silk neckerchief, and (sometimes) bell-bottom trousers.
Blue water - literally, deep water, but more traditionally, away from land. The opposite of brown water. A blue water navy is capable of prosecuting battle away from shore-based support in vessels of sufficient size and endurance to do so safely.
BMOW - Boatswain's Mate Of the Watch.
Board - To go aboard a vessel. Also, a group of persons meeting for a specific purpose, such as an investigation board.
Boat - any small vessel incapable of making regular independent voyages on the high seas; the traditional differentiator is that "ships carry boats." Also, a submarine of any size.
Boat boom - a boom to which boats secure; it is swung out from the side when the ship is anchored or moored.
Boats - nickname for a Boatswain's Mate.
Boatswain - a warrant officer or limited duty officer in charge of all deck work.
Boatswain's chair - a simple seat that can be lowered over the side to hold a man while painting. Also a more complicated chair into which a man can be strapped; used to highline personnel from ship to ship.
Boatswain's locker - a compartment, usually forward on the main deck, where line and other equipment used by the deck force is stowed.
Boatswain's Mate - enlisted rating having primarily to do with deck work.
Boatswain's pipe -  small metal whistle with a characteristic sound, used to signal the announcement of important messages, or for ceremonial purposes. In the days of sail, orders to the deck crew were given by various calls on the boatswain's pipe.
Boatswain's whistle - same as boatswain's pipe, above.
Bogey - unidentified air contact. May turn out to be friendly, neutral, or hostile. A hostile bogey becomes a bandit.
Bollard - squat cylindrical fixture attached to a pier. Used to secure lines, such as mooring lines.
Boom - projecting pole or spar that provides an outreach for handling cargo, mooring boats, etc.
Boondoggle - travel which is more fun than functional; applies to many military schools.
Boot - rookie or newbie; usually applied to enlisted men, but often heard as boot Ensign. Originated in the habit of referring to a new man as 'bootcamp,' rather than by name.
Boot camp - training camp for new enlistees. During the Spanish-American War, sailors wore leggings called boots, which came to mean a Navy (or Marine) recruit. These recruits trained in "boot" camps.
Boot topping - black paint used at the waterline of many warships; separates the hull paint from the anti-fouling underwater paint.
BOQ - Bachelor Officer Quarters; apartments and other living spaces ashore, reserved for officers without families.
Boresight - a rough method of aligning guns to a sighting system.
Bosun - phonetic spelling of boatswain; also spelled bos'n.
Bow - the forward section of a vessel. Off the bow refers to the position of an object somewhat off the heading of the ship, usually within 45º of dead ahead.
Bower anchor - either of the two anchors usually carried at the ship's bow. Most ships anchor by using one of the bowers.
Bow hook - boat crew member who tends to the lines in the forward part of the boat.
Box the compass - to name all the points of the compass. Also, to face successively in all directions, as when a ship loses steerage and drifts aimlessly.
Boyson - a young striker or apprentice; usually used by an older and more experienced salt.
Boys' town - large stateroom with bunks for six or more of the most junior officers. Sometimes called an "ensign locker."
Bracket - in shipboard gunnery, a bracket results when one salvo lands to the left of the target and the next lands to the right. Adjustments in deflection usually result in a hit soon after.
Bracket and halving - a method of correcting the aim of shipboard gunnery. For example, say a salvo falls left of the target; a spot (an aim correction) is made using right deflection, and the next salvo falls to the right of the target. Another spot is applied back to the left, half the amount of the previous correction. In this way, the fall of shot is walked onto the target.
Brass - officers, especially senior officers. Also, shell casings from small arms or larger guns whose shells have metal casings.
Brasso - commercial product used for polishing bells, belt buckles and anything else made of brass; extremely effective, but more than a little messy.
Bravo Zulu - phonetic pronunciation of 'BZ' from the NATO signals codes. Another way of saying well done.
Break out - to unstow or prepare for use. "Break out your rain gear, for there's heavy weather ahead!"
Breast line - mooring line that runs at right angles to the ship and is used to keep the ship from moving laterally away from whatever it is moored to.
Bridge - the raised deck from which the ship is steered, navigated, and conned; usually located in the forward part of the superstructure, and consists of the wheelhouse or pilot house and port and starboard bridge wings.
Brig - A jail or jail cell on a ship or naval shore base.
Brightwork - metal work, usually brass, that is kept polished rather than painted.
Broach - to be thrown broadside into the surf. Broaching is a serious problem with landing craft, and is greatly to be avoided.
Broad on the (starboard or port) beam - bearing 090º or 270º relative to the bow of the ship.
Broad on the (starboard or port) bow - bearing 045º or 315º relative to the bow of the ship.
Broad on the (starboard or port) quarter - bearing 135º or 225º relative to the bow of the ship.
Broadside - simultaneous firing of all main battery guns on one side of a warship.
Brow - the proper term for what is often called the gangway, the temporary bridge connecting the ship's quarterdeck to the pier, wharf, or float; usually equipped with rollers on the bottom and handrails on the sides.
Brown-bagger - married member of the crew. Aka khaki sacker. So called because of his presumed activity of bringing his lunch from home, carried in a brown paper bag.
Brownshoe - member of the Naval air forces, as opposed to blackshoe, or member of the surface or submarine forces.
Brown water - shallow water or shallow draft, especially a ship or navy whose ships are not suited to deep (or open) water and deep-water combat.
Brown water ops - Naval operations in shallow water, typically 100 fathoms or less.
Buck - an arbitrary object on the wardroom dining table, determining at which place food is first served. The buck moves from place to place between meals, to insure that every officer has a chance to be served first. Said to be involved in the expressions "pass the buck" and "the buck stops here."
 Bug juice - Food term: substance similar in appearance to Kool-Aid which is served as a beverage aboard USN ships; its color has no bearing on its flavor. Largely composed of ascorbic acid. Used extensively as an all-purpose cleaner/stripper for bulkheads, decks, brass fire nozzles, and pipes.
Bulkhead - vertical structure enclosing a compartment; equivalent to a wall ashore, but never called a wall.  
Bulkheading - loudly criticizing a fellow officer.
Bull Ensign - the senior ensign aboard.
Bullnose - a chock placed right over the stem, in the eyes of the ship.
Bullshit - idle chatter, frequently untruthful.
Bullshit artist - a glib person, or one who lies convincingly.
Bullshitting - lying or exaggerating, usually without sinister purpose.
Bulwark - raised plating running along the side of a vessel above the weather deck; helps keep decks dry and prevents men and gear from being swept overboard.
Bumboat - supply boat, usually of an unofficial nature; often operated by purveyors of curios, souvenirs, etc.
Bum skinny - bad information. (Skinny is information.)  "Rogers gave us bum skinny about liberty being good in Izmir."
Bunk - built-in bed aboard ship. Also called a berth or rack.
Bunker - compartment for the storage of oil or other fuel.
Buoy - floating marker anchored to the bottom, which by its shape and color conveys navigational information; may be lighted or unlighted, silent or with a bell or whistle.
Burn bag - cloth or paper bag containing classified matter that is soon to be destroyed by burning.
Busted - said of an enlisted man who is reduced in rate, usually due to some offense. Also seen as broke or broken. "That affair in the captain's cabin got Chief Clinton busted all the way back to Second Class. He was lucky he didn't get brig time."
Butter bar - Ensign/Second Lieutenant (O-1 paygrade), so called for the gold bar collar device.
Butt kit - an ashtray, especially a can-shaped one mounted on a bulkhead. Sometimes called a spit kit.
By and large - colloquial term meaning 'for the most part.' Origin of the term seems to be that a ship was considered particularly seaworthy if it could sail both by (close to the wind) and large (before the wind).
By the board - overboard; over the side.
 
C    Charlie (CHAR-lee)
dah-di-dah-dit
formerly Charlie
Cabin - the Captain's living quarters.
Camel - large float used for keeping a vessel away from the wharf, pier, or quay. A camel is in the water, while a fender is suspended above the water.
Can - short for tincan; a destroyer. Also a can-shaped buoy that marks the left side of the channel when entering port from seaward.
Candy ass - one who doesn't do his share of the work. Marines embarked aboard ship, usually with no nautical duties when underway, are often called candy ass Marines.
Capstan - the vertical barrel device used to heave in cable or lines; usually used in connection with the anchor.
Captain - the master or commanding officer of the ship.
Captain of the head - the person responsible for a head cleaning detail; a bathroom cleaner.
Captain's Mast - non-judicial disciplinary procedure, usually meted out by unit commanders for minor offenses such as fighting. Also known simply as mast.
Cardinal points -the four principal points of the compass: North, East, South, and West.
Cargo net - heavy, square net made of rope used for slinging cargo. When Marines are debarking into boats, cargo nets are placed over the side and the Marines climb down them.
Carry away - to break loose, as in "the rough seas carried away the lifelines."
Carry on - an order to resume work or duties.
Cast loose - to let go a line or lines; also cast off.
CBR warfare - Chemical/Biological/Radiological (nuclear) warfare. In different eras has been known as ABC warfare (Atomic/Biological/Chemical) and NBC warfare (Nuclear/ Biological/ Chemical).
Celestial navigation - navigation with the aid of celestial bodies. Commonly uses a sextant and Nautical Almanac. Seldom used in the Navy now.
Chafing gear - guard of canvas or rope around spars, hawsers, chocks or rigging, used to protect lines from excessive wear.
Chain of command - the succession of commanding officers through which command is exercised from superior to subordinate, and through which requests are forwarded from subordinate to superior.
Chain locker - the compartment in the bow, below the anchor windlass, where the anchor chain is stowed when not paid out.
Channel fever - anxiety to get home, or reach port.
Charlie Foxtrot - Cluster Fuck.
Charlie Noble - the galley smokestack. The most popular version of the term's origin is that Charlie Noble was an Admiral who insisted that the brass or copper galley smokestack be polished for inspections.
Charm school - training program attended by enlisted men about to be commissioned as officers.
Chart - the nautical equivalent of a road map, showing land configuration, water depths, and aids to navigation. Never referred to as a map.
Charthouse or chartroom - compartment on or near the bridge for handling and stowage of navigational equipment.
Chief - see Chief Petty Officer, below.
Chief Master at Arms - the enlisted man officially designated to keep order on the mess decks and elsewhere aboard the ship. More or less the ship's sheriff and chief of police.
Chief Petty Officer - an enlisted man in one of the three highest rates: Chief Petty Officer, Senior Chief Petty Officer, and Master Chief Petty Officer. Instead of the bluejacket's traditional sailor garb, they wear officer-like uniforms, including a special cap or hat, and they occupy a special place between the bluejackets and the officers. Because of their skills, knowledge, and experience, the Chiefs are widely recognized as "the backbone of the Navy."
Chief snipe - the Engineer Officer.
Chinese fire drill - any evolution notable for its lack of coordination and military smartness.
Chip - to remove paint or rust from metallic surfaces before applying paint. A major activity of deck apes.
Chipping hammer - small hammer with a sharp peen and face set at right angles to each other; used for chipping paint and scale from metal surfaces.
Chit - any small piece of paper bearing permission to do something, or requesting such permission. Before going on leave, you need to get a chit from the Captain or Exec. To request a change in duty, you need to submit a chit.
Chock - steel deck member, either oval or U-shaped, through which mooring lines are passed. Usually paired off with bitts.
Chockablock - completely full; full to the top; as close to one another as possible.
Chow - food.
Chronometer - an especially accurate timepiece, set to Greenwich time; used for navigation.
CIC - Combat Information Center. The compartment, usually close to the bridge, where tactical and navigational information is gathered, evaluated, and disseminated.
Cinderella liberty - liberty that expires at midnight.
Class Alfa fire -  a fire which leaves ashes. See screaming alfa.
Class Bravo fire - a fire involving flaming liquids.
Class Charlie fire - an electrical fire.
Class Delta fire - a fire involving special materials and firefighting methods, such as a fire involving flammable metals or deep fat fryer equipment.
Classified matter - information or material that would be of aid to a possible enemy if it were divulged improperly. From lowest to highest importance, classified matter is classified Confidential, Secret, or Top Secret. In the Navy and other military branches, all material of any importance to operations is classified. Since journalists almost never have access to classified matter of any sort, one can see that commercial news organizations almost never know what is really going on.
Clean bill of health - this term has its origins in the document issued to a ship showing that the port it sailed from suffered from no epidemic or infection at the time of departure.
Cleat - a small deck fitting of metal with horns, used for securing lines; also called a belaying cleat. Short piece of wood nailed to a brow or gangplank to give surer footing.
Clinometer - bridge and engine-room instrument that indicates the amount of a ship's roll or degree of list.
Close aboard - nearby.
Cluster fuck - an evolution remarkable for its significant lack of excellence. Mass confusion and chaos. Similar to a Chinese Fire Drill, etc.
CNO - Chief of Naval Operations; the senior Admiral in the Navy. Every ring knocker wants to be CNO one day, but knows that it's extremely unlikely.
CO - Commanding Officer. The captain of a vessel.
Coaming - raised framework around deck or bulkhead openings and cockpits of open boats; designed to prevent entry of water. Not always effective.
Coastie - member of the United States Coast Guard.
Coffee mess - an area, usually in a duty or working area, where coffee is made and served.
Cofferdam - the space between two bulkheads set close together, especially between fuel tanks, to use for drainage or safety.
Cold iron - engineering term meaning that the entire engineering plant has been secured. Lighting off boilers and getting steam up has always been an involved and lengthy operation, requiring anywhere from an hour to even longer before the ship could get underway; in time of war, being caught cold iron could be tactically disastrous. With the increasing usage of gas turbines, this is less of an issue—a gas turbine ship can get underway within minutes if the lube oil systems are warm.
 Collision mat - a mat used to temporarily lose a hole in a ship's hull below the waterline. Also, a food term: pancake.
Colors - the national ensign; distinguishing flag flown by a vessel to indicate her nationality. Also, the ceremonies performed at a naval activity when colors are hoisted at 0800 and hauled down at sunset.
Combatant ship - a ship whose primary mission is combat.
Command at sea - being captain of a seagoing warship; the goal, reachable by many who make the Navy a career, of every line officer.
Command Duty Officer - many ships, particularly larger ones, establish a command duty officer who is senior to the OOD while on duty—a period that usually spans several OOD watches. The command duty officer, or duty commander relieves the executive officer of some of his detailed supervisory duties, and acts as the XO's representative in that officer's absence.
Commander - An officer rank above Lieutenant Commander and below Captain. Also, another name for the executive officer. As the commanding officer is known as the captain, the executive officer is known as the commander.
Commissary - land-based Navy grocery store. Non-grocery items are sold at the exchange.
Commission - to activate a ship or aircraft; a written order, approved by Congress, giving an officer his rank and authority; the rank and authority itself.
Commission pennant - long, thin, seven-star pennant flown by a ship to indicate that she is commissioned in the U. S. Navy.
Companionway - set of steps or ladders leading from one deck level to another.
Compartment - any room or other enclosed space aboard a ship; often specifically refers to living quarters. "The electrician's mates have their racks in the E Division compartment."
Compass rose - diagram of a compass card on a chart; assists the navigator in laying out courses and directions on the chart.
COMPHIBLANT - Commander, Amphibious Forces, Atlantic Fleet. Formerly the admiral in charge of all amphibious ships in the Atlantic Fleet.
COMPHIBPAC - Pacific Fleet version of COMPHIBLANT, above.
Complement - the number, ranks and ratings of officers and men, as determined by the Chief of Naval Personnel, to be necessary to fight the ship most effectively.
Condition 1 - General Quarters (battle stations). May be modified for certain conditions, such as Condition 1-AS, in which all antisubmarine watch stations and weapons are manned, but anti-air stations may not be. Modified conditions are used to minimize crew fatigue, which can be a significant factor over a prolonged period at battle stations. Other types of modified conditions include 1-SQ (battle stations for missile launch).
Condition 1-A - on an amphibious ship, the condition where all hands are involved in unloading men and cargo and making the amphibious landing. Pronounced "one-alfa."
Condition 2 - a condition of modified General Quarters, generally used on large ships.
Condition 3 - a condition of readiness commonly associated with wartime steaming where some, usually half, of the ship's weapons are kept in a manned and ready status at all times.
Condition 4 - a condition of readiness commonly associated with peacetime steaming. There are no weapons in a ready status.
Condition 5 - a condition of readiness associated with peacetime in port status.
Conn - to direct the helmsman and lee helmsman as to movement of the helm and engine order telegraph, especially when navigating in narrow channels or heavy traffic. Similar to driving. When an officer announces "I have the conn," he is then legally responsible to give proper steering and engine orders for the safe navigation of the ship.
Conning - giving orders regarding the maneuvering of a ship.
CONUS - the CONtinental U.S.
Convoy - a number of merchant ships and/or naval auxiliaries, assembled and organized for the purpose of passage together, and usually escorted by warships and/or aircraft for the purpose of defense.
Corpen - a maneuver of a formation of ships. In its simplest form, ships in a column turn in succession, each at the same point, akin to a column movement of marching men. See turn.
Country - part of the ship where certain people live, such as officers' country, chiefs' country, snipe country, and so forth.
Course - a ship's desired direction of travel. It is not necessarily the same as the ship's heading.
Court martial - military court, authorized under the UCMJ,  for the trial of more serious offenses. There are three kinds of court martial: summary, special, and general. See also captain's mast.
Cover - a hat. Also, to put on a hat.
Covered - wearing a hat. Naval personnel do not salute when covered. Doing so is for lesser breeds of servicemen.
Coxswain - enlisted man in charge of a boat; usually acts as helmsman. Pronounced "koksun." A coxswain or cockswain was at first the swain (boy servant) in charge of the small cock or cockboat that was kept aboard for the ship's captain and which was used to row him to and from the ship. The term has been in use in England dating back to at least 1463. With the passing of time the coxswain became the helmsman of any boat, regardless of size.
CPA - Closest Point of Approach. The bearing and distance of another ship when it is anticipated to most closely cross your path, either ahead or astern.
Critter fritters - food term: fried mystery meat.
Crossbar Hotel - the ship's brig.
Crow - the rate insignia of a USN Petty Officer (E-4 and above), so-called because of the eagle surmounting the rate chevrons.
Crow's nest - a platform or tub, standing high on a mast and used by a lookout.
Cruise book - a book, similar to a school yearbook, published to commemorate long or special cruises. They are produced informally by people aboard the ship, and they contain pictures of the ship's personnel and their activities at sea and in port. The cruise book staff is chosen from men who are good at photography and drawing. The editor, usually one of the ship's junior officers, provides the written material.
Crypto - term referring to the personnel, equipment, and practices involved in coding messages so they cannot be read by those for whom they aren't intended.
Crypto board - a group of officers assigned the duty of handling coded messages.
Cumshaw - procurement of needed material outside the supply chain, usually by swapping, barter, or mutual backscratching. Often involves the barter of coffee or other food items. Officially frowned upon, but a widespread practice. The word comes from the pidgin English of the old China Fleet for "Come Ashore" money. It was usually anything useless to a sailor or ship, scavenged and saved for trade to locals for the purpose of earning a little extra liberty money.
Cunt cap - garrison cap worn by officers and CPOs. Also called a pisscutter.
Cut and run - to leave quickly; from the practice of cutting a ship's moorings in a hasty departure.
Cut of his jib - a person's general appearance. From the days of sail, when individual sails were made aboard the ship and a certain amount of individuality was expressed in the shape and size of the sails. Ships could be, and were, identified by the "cut of their jib."
 
D    Delta (DELL-tah)
dah-di-dit
formerly Dog
Damage Control - measures necessary to keep the ship afloat, fighting, and in operating condition.
Dark adapted - said of one's eyes when they have been optimized for seeing in the dark. The condition comes from spending several minutes with the eyes open in an area that is dark or illumniated only by dim red lights. Flashlights aboard ship often have red lenses, to avoid their destroying the dark adaption of those who see their light.
Darken ship - condition where all the ship's external lights are extinguished, and all inside lights are prevented from being seen from outside. In peacetime, allows all hands topside to appreciate the beauty of the heavens and the phosphoresence of the sea. In wartime, keeps the enemy from seeing the ship.
Davit - shipboard crane for lowering and raising boats. Pronounced "day-vit."
Davy Jones' locker - the bottom of the sea.
DCA - Damage Control Assistant. The officer responsible, under the Chief Engineer, for damage control and stability of a ship.
Dead ahead - directly ahead of the ship; bearing 000º relative.
Dead astern - directly behind the ship; bearing 180º relative.
Dead in the water - said of a ship that is underway but making no headway or sternway.
Dead reckoning - navigator's estimate of the position of the ship from the course steered and the distance run. Short for "deductive reckoning." Not always accurate, due to the effects of wind, currents, and tides.
Deadhead - the resistance of a magnetic compass to swinging back and forth excessively; a compass with insufficient deadhead will swing so much (due to normal movement of the ship or aircraft) that it is difficult to steer a course.
Debarkation station - the place on a ship where personnel assemble to debark in boats. On ships where debarkation is a major part of the mission, debarkation stations are marked by numbers on colored backgrounds, the numbers and colors having a specific organization.
Deck - on a ship, corresponds to the floor of a building on land. Decks below the main deck are the second deck, third deck, and so on, moving downward. Decks above the main deck are the 01 deck, 02 deck, and so on, moving upward. Also refers to work or personnel mainly involved with deck seamanship.
Deck ape - a deck hand.
Deck gray - dark color used to paint decks aboard ship. Haze gray is used on vertical surfaces.
Deck hands - personnel, usually Seamen and Boatswain's Mates, who work with and care for topside gear and equipment. A deck hand is sometimes called a deck ape.
Deck log - the official record of all the ship's activities, maintained and signed by the Officer of the Deck. It is traditional that the first log entry of a new year is made in verse.
Deck seamanship - branch of seamanship embracing the practical side, from the simplest rudiments of knot tying up to navigation; includes small-boat handling, ground tackle, steering, heaving the lead, signaling, etc.
Deep six - euphemism for throwing something overboard. Originally, the call of the leadsman signifying that the water is more than six fathoms deep, but less than seven.
Deflection - in gunnery, the adjustment of fire to the left or right.
Degaussing - treating the ship to reduce its magnetic field; used to protect the ship from magnetic mines.
Demurrage - a fine levied for not unloading a ship on time.
Department Head - an officer reporting to the Executive Officer and responsible for a department of the ship's organization. Most mid-sized ships have an operations department, a navigation department, a gunnery or deck department, an engineering department, and a supply department. Larger ships may have more, and smaller ships fewer, departments.
Deploy - to move into position for battle or other purposes. A ship or a sailor can deploy to the Mediterranean, for example.
Depth charge - large explosive charge used against submarines. It is dropped or launched from a ship, and explodes upon reaching a preset depth.
Deviation - magnetic compass error caused by the magnetic effect of metal in the ship.
Dip - to lower a flag partway in salute or in answer, then to hoist it again.
Direct fire - gunnery and fire control where the fall of shot can be directly observed by the firing unit.
Director - electro-mechanical device for directing and controlling gunfire.
Displacement - weight of water displaced by a ship. Equal to the weight of the ship.
Distance line - a light line stretched between two ships engaged in replenishment or similar operations when underway. The line is marked at 20' intervals to aid the conning officer in maintaining the proper distance between ships.
Distress signal - a flag display or a sound, light, or radio signal calling for assistance.
Ditty bag - small cloth bag with drawstring closure; usually used to hold toilet articles and the like.
Division - the smallest organizational unit aboard a ship. Usually consists of one or more officers plus a group of men responsible for a particular part of the ship's work. Also, an organization composed of two or more ships of the same type; two or more divisions make up a squadron.