(a) Description. Atlantis Semi-Submersible, Green Canyon 787 (GC 787), located at position 27°11′44″ N, 90°01′37″ 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 [NAD 83].

(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, USCG Heartland District.