33 CFR 147.831 - Holstein Truss Spar safety zone.
(a)Description. Holstein, Green Canyon 645 (GC 645), located at position 27°19′17″ N, 90°32′08″ W. The area within 500 meters (1640.4 feet) from each point on the structure's outer edge is a safety zone. These coordinates are based upon North American Datum 1983.
(b)Regulation. No vessel may enter or remain in this safety zone except the following:
(1) An attending vessel;
(2) A vessel under 100 feet in length overall not engaged in towing; or
(3) A vessel authorized by the Commander, Eighth Coast Guard District.