When a ship of the Navy is passing Washington's tomb, Mount Vernon, Virginia, between sunrise and sunset, the following ceremonies shall be observed insofar as may be practicable: The full guard and band shall be paraded, the bell tolled, and the national ensign half-masted at the beginning of the tolling of the bell. When opposite Washington's tomb, the guard shall present arms, persons on deck shall salute, facing in the direction of the tomb, and "Taps" shall be sounded. The national ensign shall be two-blocked and the tolling shall cease at the last note of "Taps," after which the national anthem shall be played. Upon completion of the national anthem, "Carry on" shall be sounded. (Art. 2185, U.S. Navy Regs., 1948)