2008-01-03 19:36:48 UTC
I notice there are many plans for building your own, that can handle short depths and sails. Ironically, many of the U-Boat historians have full mock plans to build anything from the late two man models to the early ship like vessels that would require a crew to operate.
Back when we were kids, I remember we tried to build a cat submarine. It didn't work out too well. The cat scratched at the sides, and imploded it under water, at the bottom of our pool. Cat just got wet, nothing bad happen to mittens on that voyage. We also made an ant colony that survived four weeks under water, with plants for air. That was kind of cool. The seals broke apparently after water-logging or pressure finally getting to them, and they all drown.