(a) The Secretary of Commerce may, until September 30, 1983, authorize an operator receiving or applying for operating differential subsidy under this subchapter to construct, reconstruct, or acquire its vessels of over five thousand deadweight tons in a foreign shipyard if the Secretary finds and certifies in writing that such operators application for construction differential subsidy cannot be approved due to the unavailability of funds in the construction differential subsidy account. Vessels constructed, reconstructed, or modified pursuant to this section shall be deemed to have been United States built for the purposes of this subchapter, section 1241 (b) of this Appendix, and sections 3704 to 3709 of title 46: Provided, That the provisions of section 1177 of this Appendix shall not apply to vessels constructed, reconstructed, modified, or acquired pursuant to this section.

(b) The provisions of this section shall be effective for fiscal year 1983 only if the President in his annual budget message for that year requests at least $100,000,000 in construction differential subsidy or proposes an alternate program that would create equivalent merchant shipbuilding activity in privately owned United States shipyards and the Secretary reports to Congress on the effect such action will have on the shipyard mobilization base at least thirty days prior to making the certification referred to in subsection (a) of this section.