33 CFR 140.201: General.

The Coast Guard investigates casualties occurring on the OCS including:

(a) Casualties on floating OCS facilities, MODUs, and vessels as described in 46 CFR part 4;

(b) Casualties on fixed OCS facilities as described in 33 CFR 146.30;

(c) Oil spillage exceeding 200 barrels of oil in one occurrence during a 30-day period; and

(d) Other injuries, casualties, accidents, complaints of unsafe working conditions, fires, pollution, and incidents occurring as a result of OCS activities as the Officer in Charge, Marine Inspection, deems necessary to promote the safety of life or property or protect the marine environment.