Section 147.851 - Jack St. Malo Semi-Sub Facility Safety Zone(a)Description. The Jack St. Malo Semi-Sub facility is in the deepwater area of the Gulf of Mexico at Walker Ridge block 718. The facility is located at 26°14'5.94" N, 91°15'39.99" W and the area within 500 meters (1640.4 feet) from each point on the facility structure's outer edge is a safety zone.(b)Regulation. No vessel may enter or remain in this safety zone except the following:(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 or a designated representative.USCG-2013-0874, 79 FR 52561, Sept. 4, 2014