Amends the Merchant Marine Act of 1936 to require that all government generated cargoes subject to the 50 percent tonnage requirement be transported on U.S. flag vessels or foreign vessels that will transport such cargo at the lowest landed cost. Defines "lowest landed cost" as the cost of transporting cargo from the point of final assembly to the designated port of entry abroad. Directs the Secretary of Commerce to take necessary steps to assure compliance with this Act.

Requires that government financed shipments of exports be transported in U.S. flag vessels at the lowest landed cost.