PUC — Presidential Unit Citation; a presidential award given to a ship or unit for exceptional performance (very rare).
R-C-H — Slang for a very small measurement.
Rope thimble — A loop of metal having a groove at its outer edge for a rope or cable, for lining the inside of an eye.
ROV — Remotely Operated Vehicle, an unmanned underwater vehicle that is remotely piloted either by wire or untethered, using sound.
Secure — Stop or finish a process, such as "Secure from Maneuvering Watch;" or when used as a verb, to make something safe, as in "secure the lines in the locker."
Secure the hover — Stop hover operations.
Secure the sidescan — Shut down the sidescan sonar.
Seizing — A length of cord or rope used for fastening or tying.
Sidescan sonar — A towed-fish sonar that looks to both sides to produce a high-definition of the ocean bottom.
SIOP — Single Integrated Operating Plan; the designated operating plan for nuclear war.
Sonar Shack — That part of a sub or surface ship that houses the sonar display equipment, where the Sonar Techs stand their watches. Usually close to the Bridge/Conn
Sonobuoys — A small (typically 5 inches by 3 feet) expendable buoy equipped to detect underwater sounds and transmit them by radio.
SOSUS — Sound Surveillance System; a chain of underwater listening posts located around the world in places such as the Atlantic Ocean near Greenland, Iceland and the United Kingdom — the GIUK gap, and at various locations in the Pacific Ocean. The system was designed to track Soviet submarines.
Sound-powered phone — A shipboard communication system powered only by the sound of the speaker's voice.
SPCC — Strength-Power-Communications Cable; the umbilical that supports the PTC and supplies power and communications.
Starboard — Right.
Stern — Back of a ship or sub.
SUBDEVGRUONE — Submarine Development Group One; the Navy command in charge of Operation Ivy Bells, where Mac had trained as a saturation diver.
SubSafe — A program instituted following the loss of the USS Thresher, to limit the number of openings to sea pressure in a submarine, and to make it safer in many different ways.
T-bar — A piece of metal that has a T-shape in cross-section. Used as a strength member.
TOG — Test Operations Group; a code name for the team that operated from the Halibut and Seawolf.
Topside — The outside deck of a submarine. Can also refer to the watch station at the top of the sail when a sub is underway.
Towed array sonar — A shipboard sonar system where hydrophones are attached to a towed cable about 50 yards apart. The size of the array enables the determination of the distance to contacts.
Turk's head — An ornamental knot resembling a turban in shape, made in the end of a rope to form a stopper.
Variable depth sonar — A shipboard sonar system on a telescoping shaft that can lower the sonar sensors to variable depths to get under shallow layers.
WRT — Water Round Torpedo Tank; a water tank used to flood a torpedo tube to allow a torpedo to swim out of the torpedo tube instead of being shot out with a burst of pressurized air.
XO — Executive Officer (See Executive Officer).