Section 147.837 - Marco Polo Tension Leg Platform safety zone(a)Description. Marco Polo Tension Leg Platform, Green Canyon 608 (GC 608), located at position 27°21'43.32" N, 90°10'53.01" 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:(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.CGD08-04-004, 69 FR 33858, June 17, 2004