(a) Except as provided by paragraphs (c) or (e) of this section, this subchapter applies to each offshore supply vessel (OSV) of United States flag contracted for, or the keel of which was laid, on or after March 15, 1996.

(b) Each OSV contracted for, or the keel of which was laid, before March 15, 1996, must have been constructed and inspected to comply with—

(1) The regulations in effect until March 15, 1996 (46

CFR subchapter I or subchapter T, as appropriate), as they existed at the time of construction; or

(2) The regulations in this subchapter.

(c) Each OSV permitted grandfathering under paragraph (b)(1) of this section must have completed construction and have a Certificate of Inspection by March 16, 1998.

(d) Each OSV of at least 6,000 GT ITC (500 GRT if GT ITC is not assigned), as defined in § 125.160 of this part, contracted for, or the keel of which was laid, before August 18, 2014, must be constructed and inspected to comply with--

(1) The regulations in effect until August 18, 2014 (46 CFR subchapter I), as they existed at the time of construction; or

(2) The regulations in this subchapter.

(e) Each OSV constructed and inspected in accordance with paragraph (d)(1) of this section must complete construction and have a Certificate of Inspection by August 18, 2016.

(f) The regulations in this subchapter have preemptive effect over State or local regulations in the same field.

(g) As used in this subchapter, the term “vessels contracted for” refers not only to the contracting for the construction of a vessel, but also to the contracting for a major conversion to a vessel, the contracting for the conversion of a vessel to an offshore supply vessel or liftboat, and the changing of service or route of a vessel if such changing increases or modifies the general requirements for the vessel or increases the hazards to which it might be subjected.