Damn that wasn't in the specs.
(Genesis
6:14-16) . . .Make for yourself an ark out of wood of a resinous tree. You will make compartments in the ark, and you must cover it inside and outside with tar. 15 And this is how you will make it: three hundred cubits the length of the ark, fifty cubits its width, and thirty cubits its height. 16 You will make a tso′har [roof; or, window] for the ark, and you will complete it to the extent of a cubit upward, and the entrance of the ark you will put in its side; you will make it with a lower [story], a second [story] and a third [story].