The amount of reduction in selling price which is herein termed “construction differential subsidy” shall equal, but not exceed, the excess of the bid of the shipbuilder constructing the proposed vessel (excluding the cost of any features incorporated in the vessel for national defense uses, which shall be paid by the Secretary in addition to the subsidy), over the fair and reasonable estimate of cost, as determined by the Secretary, of the construction of that type vessel if it were constructed under similar plans and specifications (excluding national defense features as above provided) in a foreign shipbuilding center which is deemed by the Secretary to furnish a fair and representative example for the determination of the estimated foreign cost of construction of vessels of the type proposed to be constructed. The Secretary of Transportation shall recompute such estimated foreign cost annually unless, in the opinion of the Secretary, there has been a significant change in shipbuilding market conditions. The Secretary shall publish notice of his intention to compute or recompute such estimated foreign cost and shall give interested persons, including but not limited to shipyards and shipowners and associations thereof, an opportunity to file written statements. The Secretary’s consideration shall include, but not be limited to, all relevant matter so filed, and his determination shall include or be accompanied by a concise explanation of the basis of his determination. The construction differential approved and paid by the Secretary shall not exceed 50 per centum of the cost of constructing, reconstructing, or reconditioning the vessel (excluding the cost of national defense features). If the Secretary finds that the construction differential exceeds, in any case, the foregoing percentage of such cost, the Secretary may negotiate with any bidder (whether or not such person is the lowest bidder) and may contract with such bidder (notwithstanding the first sentence of section
1155 of this Appendix) for the construction, reconstruction, or reconditioning of the vessel involved in a domestic shipyard at a cost which will reduce the construction differential to such percentage or less. In the event that the Secretary has reason to believe that the bidding in any instance is collusive, he shall report all of the evidence on which he acted