Build the frame that will support the mattress inside the hull of the boat. Using 2 x 4's, create the frame with two shorter pieces on the ends and two longer pieces on each side. Don't forget to add three cross members in the middle for added support. Screw all the pieces together to create the shape of the frame. Make sure that the screws are long enough to go through both pieces of wood.
If the boat doesn't fit through the bedroom doorway, cut the boat in half. Once it's in the room (Image 1), put the two halves back together using heavy duty brackets (Image 2).
Be sure to measure the dimensions of the vessel before taking it up the stairs.
With the hull removed, it actually gives the boat more stability while resting on the floor. To give the bed more security and to keep it from rocking, add four 4 x 4 feet just under the two bench seats for the boat to stand upon (Image 1). First place each of the four feet under the seats and predrill a hole through the seats and into the 4 x 4 (Image 2).