The windows could be fused into a composite skin, same as they are already doing on today's yacht hulls.
Really?! Are you sure?????? Perhaps your memory failed to remember the Lear Jets of the Deep: http://www.spiegel.de/international...in-popularity-with-millionaires-a-819643.html http://www.ussubmarines.com/submarines/phoenix_1000.php3
Aye Phart: There is a difference between Yachts and Submarines. Sorry if I have to point it out. Good luck to you.
If you had taken the time to read the links, you would realize that they are yachts, as in very expensive, mega-yacht yachts. They just happen to be able to avoid storms by submersing. P.S.- The architects of these vessels turn dreams into reality; as did Jack Northrop.