I have mentioned DELFTship in an earlier post. This is a nice software package, but a little too complicated for most of us. Bearboat by Marine Kayaks is a good package, but a little too simplistic. However, Ross Leidy has produced a donationware software package called KayakFoundry, which is simply amazing. Absolutely amazing! Select the Software tab at: http://www.blueheronkayaks.com/kayak/index.html. If you look into forums, there are folks sharing their designs. If you are interested in building your own craft, I can think of no easier way to loft your own design. Imagine building a well-designed kayak custom-built just for you, by you!