TC, I think the issue is that most of the people here on the list that will give you some advice have looked at what it costs to build a shallow ops boat and one that has a deeper range and conclude that it doesn’t really cost any more to go to a deeper depth. When they also run the numbers, they find that a sub with the dimensions you propose is outside of the budget of most home-builders. And finally, a larger sub presents launching and handling issues. There are very few large PSUBs, 1 completing construction and 1 undergoing sea trials in Europe along with a very innovative sub being built in Colombia for a US party that uses unusual hull materials that if successful, will open up opportunities for more large PSUBs. When the membership considers subs similar to the Russian tinniest sub, there are a lot of safety issues that remain difficult to resolve. Safety is paramount and the submarine community (the big boys) is very conservative, as a result they have few large catastrophes, many PSUBbers also hold these values. Don’t be discouraged, the PSUB group sees a lot of new comers approach the list with ideas of building a larger submersible with some characteristics that are out of the norm. Over time, these new comers if they are serious and stick around, usually end up with a more economical and easier to build smaller sub. Those that don’t clearly define what they want their sub to do early on and perform a lot of research and supporting calculations usually pay for it later upon launching and sea trials where stability and trim issues finally become obvious…there are a lot of sub lawn ornaments and garage queens out there. R/Jay Resepectfully, Jay K. Jeffries Andros Is., Bahamas Save the whales, collect the whole set. From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of T.C. Craig Dan, |