I'm new to this, and I have no sub, but I enjoy the topic and have visited the web site. I remember some articles a few years ago in Popular Science (I think) about subs made primarily from Plexiglas. Great Views etc. Are there designs like those on web site that you know of? Also, concerning escapes, are there buoyancy devices that can be inflated to raise a sub in trouble without having to exit it 100 feet down? Dan