What am I doing wrong

So I’ve been spending some time making a e-jet surf board
The board I’ve used is a 160l ahd windsurf board
Jet 80mm M.K. jet pump
Motor sss 360kv
Esc flyer esc 400a
48v 13s battery
Board and full gear 16kg
Rider 80kg
I’m a bit lost with what is wrong with it as I would think it should shift pretty well

Advice please


This is 2nd design

It is all back together but still performance is poor… I suspect it is down to the 6 blade impeller but I am not Overly clued up on impellers

You might want to visit foil.zone/ for DIY stuff! cheers!

Took it out yesterday and the “waterproof” hatch failed and I think I’ve fried the flier esc but before that happened it was making about 7-10mph