For some great reading and creative ideas on homebuilt submarines, go to www.submarineboat.com [1] for Doug Jackson's excellent documentation of his submarine project. The name of the site hints at the design philosophy: this is a boat that submerges. It actually looks like a landing craft but is a planing aluminum sub with an ambient pressure diver compartment.
This is a sub?! It's a very non-traditional submarine design but if you think about it, this may be one of the most usable and practical homebuilts ever conceived. I'd say that most people live some distance from interesting diving and very few are as fortunate as Karl Stanley [2] that they can moor a submarine or boat within a short distance of a great reef. So this craft can be trailered or tied up in a slip and with its 20mph speed carry you and a dive buddy to a range of interesting dive sites.
For this project Doug has taught himself design and fabrication skills needed to build his boat at a reasonable cost: aluminum welding and casting, electronics and of course general submarine design. All of these things are well covered on his website and it makes good reading.
