RE: Turbine Cat Build
It would seem like the manufacturers would be able to give you an idea of how big or small of a turbine that you'd need to push a Cat as there should be some kind of a formula to go by.
I've seen a couple of turbine scale boats of Peter Mueller's at the Toledo show plus have seen Tom Borisch's boat but neither of them running.
Have you picked out a Cat to put one of these little monsters into yet?