Typically having your yacht underwater is a bad thing. Not if you are rich enough to own the Migaloo Submersible Yacht. This luxury watercraft gives its owners the best of both worlds. They can lounge at exotic ports or quickly disappear underwater for ultimate privacy. There are five models available from eh 72- meter M2 to the gigantic 283- meter M7. The Migaloo Submarines are made of a modern acrylic pressure hull to military safety standards.