Under Parker Drilling Management Services, Ltd. v. Newton (2019) 139 S.Ct. 1881, state law supplements federal law governing matters on the outer continental shelf only to the extent that there is a gap in federal law.  If federal law already addresses the issue, it excludes state law.  This decision holds that the FLSA addresses the issue of meal and rest breaks for workers, thus excluding California meal and rest break laws from applying to workers on the outer continental shelf.