FOULING REMOVAL - Incrustation removal from watercraft. 



GABION - A metal cage filled with rock and interconnected with others to 

 form a revetment or bulkhead. 



GROIN - A shore protection structure built on the bottom or suspended in 

 the water at an angle to the shoreline to trap littoral drift or 

 retard erosion of the shote. 



GROUTING - Grout placement to underpin a coastal structure, to anchor a 

 pile in the bottom or in a structure leg, or to seal a structure. 



HOPPER BARGE - A barge or scow for transporting spoil or refuse, in- 

 cluding bottom-dump barges and hopper dredges. 



HYDRAULIC MODEL BASIN - A facility using three-dimensional wave or tide 

 motion for educational demonstrations or model testing. 



ICE PROTECTION - Prevention of damage to coastal structures by collision 

 with floating floes or bergs, or by crushing or uplift by surrounding 

 sheet ice. 



ICE STRUCTURE - An offshore island of frozen material or a protective 

 barrier of ice around an offshore structure. 



INSTRUMENT, LASER - An oceanographic instrument using collimated beams 

 of radiation. 



INSTRUMENT, RADIOISOTOPE - An instrument using high-energy radiation, 

 including means of measuring the radioactivity of samples, for 

 handling irradiated sediment samples for tracer studies, or for X-ray 

 photographing members of coastal structures. 



INSTRUMENT CABLE - Waterproof power or data transmission cable for 

 oceanographic instruments. 



INSTRUMENT DEPLOYMENT - Placement of instruments or samplers at prede- 

 termined depths or locations using, for example, automatic depth- 

 changing vehicles, free-fall probes, or buoy mooring cables. 



INSTRUMENT POWER SUPPLY - A means of producing or delivering power to 

 an instrument. 



INSTRUMENT RETRIEVAL - Location and recovery of instruments, records, or 

 samples. 



INSTRUMENT, AIRBORNE - A remote-sensing instrument mounted in a tower, 

 aircraft, or spacecraft, or a direct-measurement instrument in a 

 projectile launched through the air. 



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