46 U.S.C. § 53503

(a) In General .— A citizen of the United States owning or leasing an eligible vessel may make an agreement with the Secretary under this chapter to establish a capital construction fund for the vessel. (b) Allowable Purpose .— The purpose of the agreement shall be to provide replacement vessels, additional vessels, or reconstructed vessels, built in the United States and documented under the laws of the United States, for operation in the foreign or domestic trade of the United States or in the fisheries of the United States.