CLINOMETER . A device for measuring the amount of 

 roll aboard ship. 



CLK . U. S. Navy designation for a Hunter Killer 

 Ship. 



CLOSED CIRCUIT SCUBA . In the simplest type of 

 closed circuit equipment, oxygen is stored in 

 cylinders under high pressure, and is admitted to 

 a breathing bag either (1) through a manually 

 operated valve, (2) by a slow steady flow through 

 a pressure reducing valve, or (3) through a demand 

 valve system similar in construction to that 

 described for the OPEN CIRCUIT equipment. When 

 methods (2) or (3) (automatic oxygen supply )are 

 used, a manually operated emergency valve is also 

 fitted . Oxygen admitted into the breathing bag 

 mixes with the reservoir of purified exhaled gas. 

 The swimmer inhales from the breathing bag through 

 a check valve. The slight pressure of exhalation 

 closes the inhaling valve and opens an exhaling 

 valve causing the exhaled gas to re-enter the 

 breathing bag through a canister which contains 

 carbon dioxide absorbent, normally soda-lime or 

 BARALYME. The rate of oxygen utilization from 

 the cylinders is determined by the diver's meta- 

 bolic consumption of oxygen rather than by the 

 larger volume of gas required for ventilation as 

 in the open circuit type. Because of the danger 

 of oxygen poisoning, present operating doctrine 

 limits use of closed circuit oxygen apparatus to a 

 depth of 30 feet for a period of 45 minutes. (37) 



CLOSED SEA . 1. That part of the ocean enclosed 

 by headlands, within narrow straits, etc. 



2. That part of the ocean within 

 the territorial jurisdiction of a country. The 

 opposite is open sea. (17) 



CLOUD . 1. A visible assemblage of numerous tiny 

 droplets of water, or ice crystals formed by con- 

 densation of water vapor in the air, with the base 

 above the surface of the earth. Clouds may be clas- 

 sified according to some common characteristic, as 

 high clouds, middle clouds, low clouds, or clouds 

 with vertical development. High clouds may be fur- 

 ther classified as cirrus, cirrocumulus , or cir- 

 rostratus. False cirrus is the debris of the up- 

 per frozen parts of cumulonimbus . If in the form 

 of a cap or hood it may be called a cap cloud. 

 Middle clouds may be further classified as alto- 

 cumulus or altostratus. Low clouds may be further 

 classified as stratocumulus, stratus, or nimbostra- 

 tus . A characteristic raincloud is sometimes 

 called nimbus. Clouds with vertical development 

 are classified as cumulus or cumulonimbus. Such a 

 cloud having an anvil-like upper part may be called 

 an anvil cloud. A thundercloud is a cumulonimbus 

 or well-developed cumulus. Large, rounded cumulus 

 with light edges, often appearing before a thunder- 

 storm, may be called thunderhead. Prefixes such 

 as alto-, or cirro-, are combining terms, used to 

 indicate cloud height, while cirriform, cumuliform, 

 and stratiform are terms describing clouds pertain- 

 ing to or resembling the general form of their 

 respective prefixes. Basic cloud names may also 

 be modified by suitable adjectives, to better de- 

 scribe their appearance, as lenticular, having the 

 shape of a lens; mamma tus , having the form of 

 pouches or breasts; radiatus, having parallel bands 

 apparently radiating from a point on the horizon; 

 and undulatus , having elongated and parallel ele- 

 ments , as ocean waves. Fracto- is a prefix indi- 

 cating a torn, ragged, scattered appearance. Clouds 

 may be classified according to their position, as 

 a stationary cloud or standing cloud appearing 

 over a mountain peak or ridge. Such a cloud rest- 

 ing over a mountain peak is called a cap cloud or 

 banner cloud. One over a mountain ridge is called 

 a crest cloud. A crest cloud may be called sansan 

 in the Canadian Rockies, or tablecloth if appear- 

 ing over Table Mountain in South Africa. A scarf 

 cloud is a thin cirrus-like cloud sometimes ob- 



served above a developing cumulus. Squall clouds 

 are small eddy clouds formed below the leading 

 edge of a thunderstorm cloud. Clouds may be classi- 

 fied as to their shape. A funnel cloud is the 

 characteristic tornado cloud; a pocky cloud is one 

 having the under surface in the form of pouches or 

 breasts; mares' tails originate as long slender 

 streaks of cirrus. Scud consists of shreds or 

 small detached masses of rapidly-moving clouds. A 

 veil is nearly invisible, it may be called fumulus . 

 Wisps or falling trails of precipitation are called 

 virga. An iridescent cloud is one having brilliant 

 spots or a border of colors. Such a cloud seen in 

 the stratosphere during twilight is called a nac- 

 reous cloud or mother of pearl cloud. A similar 

 assemblage in contact with the surface of the earth 

 is called fog. 



2. A visible assemblage of tiny particles 

 of any substance, as a dust cloud. 



3. Star cloud. (17) 



CLOUD CLASSIFICATION . A system of grouping cloud 

 types according to some common characteristic. The 

 groups commonly used are: a. high clouds (mean 

 lower level above 20,000 feet), consisting of cir- 

 rus, cirrocumulus, cirrostratus ; b. middle clouds 

 (mean level 6,500 to 20,000 feet), consisting of 

 altocumulus, altostratus; c. low clouds (mean 

 upper level under 6,500 feet), consisting of strato- 

 cumulus, stratus, nimbostratus ; d. clouds with 

 vertical development, consisting of cumulus and 

 cumulonimbus. (17) 



CMC . Commandant, Marine Corps. 



CMM . Commission of Maritime Meteorology. 



CMR . Common Mode Rejection. 



CNO. Chief of Naval Operations. 



CNRS . Centre National de al Recherche Scientifique. 



COAST . A strip of land of indefinite width (may be 

 several miles) that extends from the seashore in- 

 land to the first major change in terrain features. 

 (11) 



COASTAL AREA . The land and sea area bordering the 

 shore line. (11) 



COASTAL ICE . See FAST ICE. 



COASTING LEAD . A light deep sea lead (30 to 50 

 pounds), used for sounding in water 20 to 60 fathoms. 

 (17) 



COAST LINE . (1) Technically, the line that forms 

 the boundary between the COAST and the SHORE. 



(2) Commonly, the line that forms the 

 boundary between the land and the water. (11) 



COAXIAL CABLE . A transmission line consisting of 

 one conductor, usually a small copper tube or wire, 

 within and insulated from another conductor of lar- 

 ger diameter, usually copper tubing braid. The 

 outer conductor may or may not be grounded. Radia- 

 tion from this type of line is practically zero. 

 Coaxial cable is sometimes called concentric line. 

 (36) 



COCKEYED BOB . A thunder squall occurring during 

 the southern hemisphere summer, on the northwest 

 coast of Australia. (17) 



CO-CUMULATIVE SPECTRUM . (Abbreviated CCS.) In 

 ocean-wave studies, the integral of an energy 

 spectrum. The area under a particular energy 

 spectrum from a given frequency value to infinity 

 is given by the value of the CCS. curve at that 

 frequency. (24) 



COCKTAIL PARTY EFFECT . Anyone who has ever at- 



24 



