I am glad someone is doing a PT boat. I am building a 48 inch boat using a framing kit from John Drain in Australia. The hull came out beautifully, but I did have a few problems mounting the stuffing boxes. I am running three Graupner Speed 600 motors. Would have like to use gear boxes but it didn't fit with the motor mounting configuration which is a shame since the boat hull actually looks like the real thing. I am powering the boat with 3 battery packs comprised of 10 DCell batteries each. The batteries packs are rated at 12V10AmH each. We have calculated that it should give us about 1 hour run time http://www.batteryspace.com/index.as...S&Category=904. I have had many discussions with people on this website and opted for three separate speed controlers. I had a hard time finding anything but expensive Castles but eventually settled on some one that I got through the internet that have a 70AmH rating forward and a 30Amh rating backward. They were significantly cheaper than that recommended by people on this website and in some test actually performed better than what they supplier stated. With a major motor like a drill motor you will draw more amps so you need to really sit down and think this out. How many motors will you run? What size prop are you planning for? What is the Amp draw of each motor? What type of drive system are you planning? What type of Batteries are you planning to use? I can't wait to hear you answers since they might give me clues into what I should be doing. I do know that John Drain has designed his 48 incher to handle a zenoaha engine (www.pt-boats.com).. He also has some serious designs for the guns and torpedos. We have already tested his torpedo design in the pool and they really work well. Good luck. Please keep in contact as you build this. My goal was to do it totally electric, but I might be interested in moving to fuel if yours works well. I will try to put some pictures of my completed hull with drive, power, battery and control systems on the wed in the near future.