In the Dutch adventure park EFTELING, you can ride the wild water track PIRANHA.

It is currently long-time out-of-order due to big maintenance, so I thought it would be nice to build a cart for my garden pond. At least I have one running than :-)

Still working on it. I will publish it in separate parts soon,
this is the mockup till now...

ORCA rebuilt to Arduino/Ramps

Best to print the floater with no infill and fill it with polyurethane foam.