To the SUP foilers out there.
The family and I are looking at getting an Inflatable boat IRB, similar to the lifesaving rescue boats.
My question is what is the minimum HP outboard motor size people have used successfully when towing and getting a SUP foil up on foil?
I am thinking of a 12ft Inflatable with a 20-25hp outboard and max 3-4 people on board boat.

Fanatic Allwave 9', Fanatic 8'7" Stubby Foil Edition

That'll do fine, you don't need much speed to get up on foil.

Depends on the foil more than board but if the foil is big enough to get the sup up, then the boat won't have any problems

Thanks, beefarmer thought it would be, but just wanted to make sure.

A mate (80kg at the time) managed to get foiling behind a tinny with a 9hp on it. 25 will sh!t it in!