I talked to NICHOLAS (Nick) LEASON yesterday. I think he is the owner of Lift Foil. I emailed them awhile back but no response so decided to give them a call.
According to Nick, their eFoil setup uses a very powerful ducted thruster. Somewhere in the 6KW range. This is a custom design that they manufacture. Their battery pack is no lightweight in terms of power.
I got interested in the eFoil because of my fishing kayak project, but it became obvious to me while talking to Nick their thruster/controller/battery setup was way more than I needed. When I mentioned to Nick my hull speed was around 4 mph he laughed and said their setup would probably be able to get my kayak to plane, even without their foil setup.
From what I read on their site the eFoil setup will run for about an hour at 15 mph with a max speed around 25 mph.
I would strongly suggest giving Nick a call at +1 787 609 6198. They are located in Aguadilla, Puerto Rico (EST).