KiteDevil said...
on a surfboard and at that weight go the 10, or maybe the 8m.
He already has an 8M and thats why I am recommending a 12M, otherwise too much overlap and he wants to get out in light conditions.
The 12M Light XC behaves like a smaller kite, and will give very good bottom end for a 70kg rider, and good overlap with an 8M Light XC too.
Cya and
Goodwinds
Steve