Thought you gents might be interested in seeing this Swiss project that's related to the hobby. Who knows, perhaps you can help them take it mainstream into mass production.
A new breed of robot fish that is both relatively inexpensive and highly customizable is teaching students between the ages of 10 and 18 about technology and biology. It's the latest in a line of biologically-inspired underwater robots developed within the naro (nautical robots) project at ETH Zurich (Swiss Federal Institute of Technology), which has previously developed robots based on tuna fish and sea turtles.