33 CFR §147.1104

1. (a)Description: The areas within a line 500 meters from each point on the outer edge of each structure. The structures are approximately 120 meters apart. The position of the center of each structure is: Platform Ellen, 33°-34′-57″ N, 118°-07′-42″ W; and Platform Elly, 33°-35′-00″ N, 118°-07′-40″ W.
2. (b)Regulations: No vessel may enter or remain in this safety zone except the following: (1) An attending vessel serving either structure, (2) a vessel under 100 feet in length overall not engaged in towing, or (3) a vessel authorized by the Commander, USCG Southwest District.