Secure area means the area on board a vessel or at a facility or outer continental shelf facility, over which the owner/operator has implemented security measures for access control, as defined by a Coast Guard approved security plan. It does not include passenger access areas or public access areas, as these terms are defined in 33 CFR 104.106 and 105.106 respectively. Vessels operating under the waivers provided for at 46 U.S.C. 8103(3)(A) or (B) have no secure areas. Facilities subject to 33 CFR chapter I, subchapter H, part 105 may, with approval of the Coast Guard, designate only those portions of their facility that are directly connected to maritime transportation or are at risk of being involved in a transportation security incident as their secure areas.
49 CFR § 1570.3
In addition to the definitions in 1500.3, 1500.5, and 1503.202 of subchapter A, the following terms are used in this subchapter: