Any vessel or class of vessels, the keel of which was laid or which was at a corresponding stage of construction before December 24, 1980, provided that she complies with the requirements of -
(a) The Act of June 7, 1897 (30 Stat. 96), as amended (33 U.S.C. 154-232) for vessels navigating the waters subject to that statute;
(b) Section 4233 of the Revised Statutes (33 U.S.C. 301-356) for vessels navigating the waters subject to that statute;
(c) The Act of February 8, 1895 (28 Stat. 645), as amended (33 U.S.C. 241-295) for vessels navigating the waters subject to that statute; or
(d) Sections 3, 4, and 5 of the Act of April 25, 1940 (54 Stat. 163), as amended (46 U.S.C. 526b, c, and d) for motorboats navigating the waters subject to that statute, shall be exempted from compliance with the technical Annexes to these Rules (33 CFR parts 84 through 88) as follows:
(i) The installation of lights with ranges prescribed in Rule 22 (§ 83.22), vessels of less than 20 meters in length are permanently exempt.
(ii) The installation of lights with color specifications as prescribed in Annex I to these Rules (33 CFR part 84), vessels of less than 20 meters in length are permanently exempt.
(iii) The repositioning of lights as a result of conversion to metric units and rounding off measurement figures are permanently exempt.
(iv) The horizontal repositioning of masthead lights prescribed by Annex I to these Rules (33 CFR part 84), vessels of less than 150 meters in length are permanently exempt; and
(v) Power-driven vessels of 12 meters or more but less than 20 meters in length are permanently exempt from the provisions of Rule 23(a)(i) and (iv) (§ 83.23(a)(i) and (iv)) provided that, in place of these lights, the vessel exhibits a white light aft visible all-round the horizon.