CURRENT, FEEDER . The current which flows parallel 

 to shore before converging and forming the neck of 

 a rip current. See also RIP. (11) 



CURRENT. FLOOD . The movement of the tidal current 

 toward the shore or up a tidal stream. (11) 



CURRENT HOUR . The mean interval between the transit 

 of the moon over the meridian of Greenwich and the 

 time of the strength of flood current modified by 

 the times of slack water and strength of ebb. In 

 computing the mean current hour an average is ob- 

 tained of the intervals for the following phases: 

 Flood strength, slack before flood increased by 

 3.10 hours (one-fourth of tidal cycle), slack after 

 flood decreased by 3.10 hours, and ebb strength 

 increased or decreased by 6.21 hours (one-half of 

 tidal cycle). Before taking the average, the four 

 phases are made comparable by the addition or re- 

 jection of such multiples of 12.42 hours as may be 

 necessary. The current hours is usually expressed 

 in solar time, but if the use of lunar time is 

 desired, the solar hour should be multiplied by the 

 factor 0.965. (14) 



rent out from an observing vessel, its direction 

 and the amount of line passing over a fixed refer- 

 ence point during a specified time Interval indi- 

 cate the direction and velocity of the current. 

 (14) 



CURRENT. RIP (RIP SURF) . A narrow current of water 

 flowing seaward through the breaker zone. A rip 

 current consists of three parts: (1) The "feeder 

 currents" flowing parallel to the shore inside the 

 breakers; (2) the "neck" - where the feeder currents 

 converge and flow through the breakers in a narrow 

 band or "rip"; and (3) the "head" - where the cur- 

 rent widens and slackens outside the breaker line. 

 (11) 



CURRENT ROSE . A graphical representation of cur- 

 rents, usually by 1° quadrangles, using arrows for 

 the cardinal and intercardinal compass points to 

 show resultant drift and frequency of set for a 

 given period of time. (15) 



CURRENT. STREAM . A narrow, deep, and fast-moving 

 ocean current. (11) 



CURRENT, INSHORE. A current inside the BREAKER 



ZONE. 



(11) 



CURRENT LINE (LOG LINE) . A graduated line attached 

 to a current pole and used in measuring the velocity 

 of the current. The line is marked in such a man- 

 ner that the velocity of the current expressed in 

 knots and tenths is indicated directly by the 

 length of line carried out by the current pole in 

 a specified interval of time. When marked for a 

 60-second run, the principal divisions for the 

 whole knots are spaced 101.33 feet and the sub- 

 divisions for tenths of knots are spaced at 10.13 

 feet. (14) 



CURRENT, LITTORAL . The nearshore currents pri- 

 marily due to wave action, e.g. LONGSHORE CURRENTS 

 and RIP CURRENTS. (11) 



CURRENT, LONGSHORE . The inshore current moving 

 essentially parallel to the shore, usually generat- 

 ed by waves breaking at an angle to the shore line. 

 (11) 



CURRENT METER . An instrument for measuring the 

 velocity of a current. It is usually operated by 

 a wheel equipped with vanes or cups which is ro- 

 tated by the action of the impinging current. A 

 recording device is provided to indicate the speed 

 of rotation which is correlated with the velocity 

 of the current. See also EKMAN, PETTERSSON, PRICE, 

 and RADIO CURRENT METERS. Other current meters 

 include the Witting, Rauschelback, Sverdrup-Dahl, 

 Fjeldstad, Roberts, Von Arx, Iwamiya, Nanniti, Ono, 

 BBT-Neyrpic, Dunderque, Chausey, Ott, Bohnecke, 

 Komatsu, Pegram, Winters, Carruthers, Idroc, Mosby, 

 Hydrowerskstaten, Snodgrass, etc. (14) 



CURRENT. OFFSHORE . (1) Any current in the off- 

 shore zone; (2) Any current flowing away from 

 shore. (11) 



CU RRENT. PERMANENT . A current that runs continuous- 

 ly independent of the tides and temporary causes. 

 Permanent currents include the fresh water discharge 

 of a river and the currents that form the general 

 circulatory systems of the oceans. (11) 



CURRENT POLE . A pole used in observing the direc- 

 tion and velocity of the current. The standard 

 pole used by the Coast and Geodetic Survey is about 

 3 inches in diameter and 15 feet long and is 

 weighted at one end to float upright with the top 

 about 1 foot out of water. Shorter poles are used 

 when necessary for shallow water. In use, the pole 

 is attached to the current line but is separated 

 from the graduated portion by an ungraduated sec- 

 tion of approximately 100 feet which is known as 

 the stray line. As the pole is carried by the cur- 



CURRENT SYSTEM, NEARSHORE . The current system 

 caused primarily by wave action in and near the 

 breaker zone and which consists of four parts: the 

 shoreward mass transport of water; longshore cur- 

 rents; seaward return flow, including rip currents; 

 and the longshore movement of the expanded heads of 

 rip currents. (11) 



CURRENT, TIDAL . A current, caused by the tide- 

 producing forces of the moon and the sun, which is 

 a part of the same general movement of the sea 

 manifested in the vertical rise and fall of the 

 tides. (11) 



CUSP (BEACH CUSP) . One of a series of naturally 

 formed low mounds of beach material separated by 

 crescent-shaped troughs spaced at more or less 

 regular intervals along the beach face. (11) 



CUSS I . Continental, Union, Shell and Superior Oil 

 Companies barge and drill rig used during the first 

 MOHOLE work in 1961. 



CUW. Committee on Undersea Warfare of the National 

 Academy of Sciences - National Research Council. 



CV. U. S. Navy ship designation for an Aircraft 

 Carrier. 



CVA . U. S. Navy ship designation for an Attack 

 Aircraft Carrier. 



CVB . U. S. Navy ship designation for a Large Air- 

 craft Carrier. 



CVE . U. S. Navy ship designation for an Escort 

 Aircraft Carrier. 



CVHA. U. S. Navy designation for a Helicopter 

 Assault Ship. 



CVL. U. S. Navy ship designation for a Small Air- 

 craft Carrier. 



CVS . U. S. Navy ship designation for an ASW 

 Support Aircraft Carrier. 



CYCLE . A cycle is the complete sequence of values 

 of a periodic quantity that occurs within one 

 period. (9) 



CYCLIC SALTS . Salts which have been introduced 

 into the atmosphere from the sea surface by evapor- 

 ation and bursting bubbles. They are carried in- 

 land by the atmosphere, deposited or carried down 

 by rain and snow and are eventually carried back 

 to the sea by streams. 



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