Here is an entry for the Autodesk kinetic contest, the idea behind this is to be able to have a snowmobile during the winter and then easily convert it to a jet ski in the summer! The idea is that you have the engine turn the snowmobile tracks as normal, but to also have it hooked up to something like a tractor PTO so you can hook up the propeller for the jet ski. The rest is just a jet ski shell you put over the tracks,(the tracks will also have to be disengaged). This is just a project I have had in my head for a long time now, but its a little to big for me to tackle so I figured I would put it out their and see if someone else might want to try it.
To get the full view download the google sketch up model here: