I put an M701C Jet Engine on an Inflatable iSUP Paddle Board and fun was had.
The support boat clocked 22 MPH using GPS at a point where the SUP over took it.
In excess of 25 MPH? That's pretty quick for a SUP!
Farrel O'Shea & Adam Whipp were the pilots and Tim Mackley & Will Parry were the support crew.
Details of the Jet SUP build can be locate here:
https://www.jetpower.co.uk/superjumbojet