That's about stupid. If you are going to build a robot that swims, why would you make it humaniod in form? Robotuna is way cooler:
www.engadget.com/.../
An improved model will be out soon incorporating lesons learned from recent Olympics.
Next version will be able to take three dolphin kicks on breaststroke pullouts.
"In research on swimming one problem is it is hard to know how much propulsive force the hands create during the stroke."There's a book called Swimming Fastest which may help unlock the mystery.