Sec. 4.
That all vessels and other property or interests of whatsoever kind, including vessels or property in course of construction or contracted for, acquired by the President through any agencies whatsoever in pursuance of authority conferred by the Acts or parts of Acts repealed by section 2 of this Act, or in pursuance of the joint resolution entitled "Joint resolution authorizing the President to take over for the United States the possession and title of any vessel within its jurisdiction, which at the time of coming therein was owned in whole or in part by any corporation, citizen, or subject of any nation with which the United States may be at war, or was under register of any such nation, and for other purposes," approved May 12, 1917, with the exception of vessels and property the use of which is in the opinion of the President required by any other branch of the Government service of the United States, are hereby transferred to the board: Provided, That all vessels in the military and naval service of the United States, including the vessels assigned to river and harbor work, inland waterways, or vessels for such needs in the course of construction or under contract by the War Department, shall be exempt from the provisions of this Act.