Carl -- thanks for all the info, bound to be helpful. Can't say I blame you for being skeptical about this project. I'm still a bit skeptical myself!
PaulC -- thanks for the tip, I'll try to contact this guy.
I'm don't have much doubt I can produce a workable hull in this size. The part I'm more concerned about is propulsion. I'm not sure if there is anything suitable made for this purpose, and I don't have machining equipment to make or adapt anything else. Though I've been drooling over a certain mini-lathe for some time now...
Anyone know of a good source for larger motors & ESCs made for model boats? Like I said, I don't care if this thing is underpowered, as long as it can slowly maneuver, hopefully even with a little wind/chop.
I'm used to being told "it can't be done". I got a lot of that when I began work on the Horten 229 (see http://www.wingsontheweb.com/ho229/
). For me, that's a great motivator!
As someone already posted, the background of the I-400 is a fascinating story. This was the largest submarine built during WWII, but so secret that we didn't know about it until the surrender. Here are some links that will give you an idea:
http://www.armorama.com/modules.php?op= ... e&sid=2631
If this piques your interest, buy the new book, which has a lot of newly discovered details, "I-400: Japan's Secret Aircraft-Carrying Strike Submarine" by Henry Sakaida, Gary Nila and Koji Takaki.
Oh, and if you're ever in the Washington D.C. area, you can see the world's only remaining piece of hardware from this project, a restored Seiran on its beaching gear. It's at the Udvar-Hazy Center of the National Air & Space Museum at the Dulles Airport in Virginia. See http://www.nasm.si.edu/