I used to race Naviga M Class back in the day. 10cc glow engine IIRC. Here's a taster...
http://www.youtube.com/watch?v=BgShkE-TojA
I think you might be able to see why I gave it up and switched to RC cars! There is a lot of skill involved but the course isn't exactly the type of challenge I was looking for!
Check out the Model Power Boat Association - their gas-engine classes go up to 35cc and 80+ mph - crazy!!
