what a wonderful response. Thank you very much for your insightful and expert advice!
I'm 84kgs and would like him on his own board as soon as possible. But I won't push it. Maybe 3-4wks = 3-4windsurf sessions at a weekend for us.
I'll take a look at the Starsurfers & Sailworks Retro Ripper at the weekend
as his first board. In the interim I'll ride a Go L with him until he's tacking and staying up win all the time.