There's a DIY forum for building those[1] but I think tow boogies[2] are more practical as a project. The idea is a battery box, controller, and motor on a boogie board and shifting the weight of the person being towed allows for steering.
Since the original article is about human power, I'll also link to this foil[3] which is for pump foiling long distance. I had run across the channel well before that and thought his goal for a half hour was goofy when people were getting 90s or 2 minutes so I was quite shocked when it actually got built.
[1] https://foil.zone/ [2] https://www.youtube.com/watch?v=S9z6BP8Y42U
Since the original article is about human power, I'll also link to this foil[3] which is for pump foiling long distance. I had run across the channel well before that and thought his goal for a half hour was goofy when people were getting 90s or 2 minutes so I was quite shocked when it actually got built.
[3] https://www.youtube.com/watch?v=WfJbF0xkUOY