the car ferry is owned by a common carrier by water and operated as part of a rail route with the approval of the Surface Transportation Board;

the stock of the common carrier by water, or its predecessor, was owned or controlled by a common carrier by rail prior to June 5, 1920;

the stock of the common carrier owning the car ferry is, with the approval of the Board, now owned or controlled by a common carrier by rail; and

the car ferry is built in and documented under the laws of the United States.