OFFSHORE ISLAND - A mamnade island of rubble. Ice, or fill. 



OFFSHORE MOORING STRUCTURE - An unprotected structure for mooring ships 

 in the open sea, including buoys with patented anchoring systems, 

 bottom-supported mooring platforms, and docks for service boats on 

 offshore drilling platforms. Does not include mooring buoys without 

 new anchoring systems. 



OFFSHORE PLATFORM ANCHOR - An anchoring means specifically for resisting 

 the uplift or lateral motion of a buoyant offshore stinicture. 



OFFSHORE PLATFORM, FIXED - A platform founded in the bottom and supported 

 by rigid legs. 



OFFSHORE PLATFORM, FLOATING - A floating drilling or mooring platform 

 with patented anchoring system. When used with OFFSHORE PLATFORM, 

 FIXED or OFFSHORE PLATFORM, JACK UP, signifies that the platform 

 either is moored to a fixed platform or is semisubmersible and may be 

 sunk until supported by the bottom in shallow water. 



OFFSHORE PLATFORM, JACK UP - A platform equipped with vertically movable 

 legs that are lowered to the bottom to support the working deck above 

 the water's surface, including devices for changing the vertic^ 

 position of the legs. 



INSTRUMENT, SEABED IN SITU - An instrument placed in or on the bottom for 

 measuring the seabed's mechanical, electrical, or chemical properties 

 in place. 



INSTRUMENT, TOWED - Any oceanographic instrument towed through the water 

 or across the bottom, except seismic surveying gear. 



JETTY - A struttture extending into a body of water at the mouth of a 



river or tidal inlet, designed to help deepen and stabilize a channel 

 by preventing shoaling by littoral material and by directing and con- 



^ fining the stream or tidal flow. 



LOW-COST SHORE PROTECTION - A shore protection structure, such as a 



revetment, seawall, or breakwater, that a private landowner can con- 

 struct to protect beach-front property. 



OFFSHORE CAISSON - A large hollow structure placed seaward of the breaker 

 zone, Including, for example, modular units for breakwaters, oversize 

 legs for platforms, and rigid pollution barriers around platforms. 



OFFSHORE CONSTRUCTION - Assembly of a coastal structure on or under the 

 water's surface and placement of a structure on or in the bottom. 

 Does not include means of transporting the structure to the con- 

 struction site. 



OFFSHORE HARBOR - A manmade structure not connected with the shore, 

 forming an enclosure for mooring and protecting ships. 



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