(a) In General.— The Secretary of Transportation may acquire a vessel, by purchase or otherwise, if
(1) the Secretary considers the vessel necessary to establish, maintain, improve, or serve as a replacement on an essential service, route, or line in the foreign commerce of the United States, as determined under section
50103 of this title;
(2) the vessel was constructed in the United States; and
(3) the Secretary of the Navy has certified to the Secretary of Transportation that the vessel is suitable for economical and speedy conversion into a naval or military auxiliary or otherwise suitable for use by the United States Government in time of war or national emergency.