(a) This subpart applies to MODUs, floating OCS facilities, and vessels, other than offshore supply vessels regulated under subchapter L of this chapter, constructed after April 2, 2018 that engage in OCS activities.

(b) U.S. MODUs, floating OCS facilities, and vessels other than OSVs regulated under subchapter L of this chapter and U.S. tank vessels that carry flammable and combustible cargoes, may comply with this subpart in lieu of §§111.105-1 through 111.105-15. All other sections of subpart 111.105 of this part remain applicable.