Appendix A
NAUTICAL LEXICON

AFT:

toward the rear of a ship.

AIR MANIFOLD:

an array of valves and gauges in the control room that regulates and directs the high-pressure air supply in the submarine.

AIR VENT:

a vent in the top of a ballast tank that allows air to escape so that the tank can fill with seawater.

BALLAST TANKS:

large tanks (usually) located outside a submarine’s pressure hull, used to control the sub’s buoyancy by filling with varying amounts of seawater.

BILGE:

a space inside the hull, but beneath the deck, containing machinery and other components that don’t require easy access and acting as a sump for water and oil.

“BOSUN”:

short for “boatswain,” a petty officer in charge of rigging, sails, anchors, and other deck activities.

BREAST DRILL:

a hand drill configured like a manual egg beater, with a padded end and a side-mounted hand crank.

BULKHEAD:

a partition between compartments, usually reinforced and watertight.

CHIEF PETTY OFFICER:

a senior enlisted rating, assigned to leadership positions. (See Appendix B.)

CONNING TOWER:

a flattened cylindrical tower extending above a submarine’s deck containing the steering platform, periscopes, and bridge.

CRASH DIVE:

an emergency dive, usually performed during wartime, when a submarine is either under attack or preparing to attack another ship.

DIVING RUDDER:

an adjustable horizontal plane on either side of the hull, usually at both bow and stern, which directs the sub’s motion either up or down.

ENSIGN:

the lowest rank for naval officers, except for Midshipman. (See Appendix B.)

FATHOM:

a nautical measure of depth: one fathom equals six feet.

FORWARD:

toward the front end of a ship.

HEAD:

shipboard restroom, derived from the days of sail, when crewmen retired to the cutout seats in the rigging beneath the bowsprit (that is, in the “head” of the ship).

HEAVE TO:

nautical term for bringing a vessel to a halt.

HELM:

general term for a ship’s steering mechanism.

KINGSTON VALVE:

valve located in the bottom of a ballast tank to let in seawater.

KNOT:

nautical unit of speed. One knot equals one nautical mile (6,080 feet) per hour, or a little more than one and one-sixteenth statute mile per hour.

LEAD-ACID CELL:

single component of the electrical storage battery used in submarines and automobiles.

MAIN INDUCTION VALVE:

a large valve used to ventilate the interior of a submarine.

“OLD MAN”:

slang term for a device used to insert torpedoes into their launching tubes.

PORT:

left, or the left side of a ship.

RATCHET DRILL:

a hand drill with an internal ratchet that converts forward pressure into rotation.

STARBOARD:

right, or the right side of a ship.

STERN:

the aft end of a ship.

TORPEDO:

a motorized underwater missile, either guided or unguided.

WINDLASS:

a cylindrical turnstile, used to pull in cables and anchor chains.