A bill to provide for participation of subsidized vessels in a Sealift Readiness Program of the Department of Defense, and for other purposes.

Amends the Merchant Marine Act, 1936, to require that all ships built with construction- differential subsidy funds appropriated after June 25, 1978, be offered to the Secretary of Defense for enrollment in the Sealift Readiness Program. Makes the owner of such a vessel liable to refund a specified portion of the construction-differential subsidy to the Secretary of Commerce for failure to offer such vessel for such enrollment.

Prohibits a contract for the payment of such subsidy to be made or extended after the date of this Act unless the owner has already offered the vessel for enrollment.

Directs such owners to offer such vessels for enrollment within 30 days of the date of this Act.