Never heard of them.
Hamilton would certainly be the miost common. We have three main streams of Jetboating in NZ. Pleasure, Jetsprinting and Marathon. When I was a young lad, my Boss was World Champion for Marathon Jetboating 3 times. I remember the first year some Canadians came over here with there boats. It showed us Kiwis that there were other alternatives to the Hamilton. Ideas a designs have flowed forth ever scince from several Kiwi backyard inventors. Nothing new as far as the Jet part, it was in how the water
was controlled that we have seen the biggest changes. Hamiltons used to be large volume jets of water
. Berckley used a very small jet of water under much higher pressure, thus more velocity. Not good at getting off the mark, but once up on top of the water under speed, those boats flew. But that was 30yrs ago now and many changes and designs have been made scince.