wdric said..
Are the guys who use them for racing strapless or strapped?
Hey Ric
it seems like most of the guys are racing with their hydrofoils with straps
however I would recommend to learn with only one strap: it helps to find balance at the begining and you're out faster when crashing ('cause it happens a lot at the begining!)
Some guys have two "head" of the foil for different wind confitions: a wider one for lighter days, and a thin one for windier days
Check this video of Alex Caizergues riding his foil: