Hi Youngbull,
Yep, done it a while ago. Towed Andy Rawson back from a heat at Jurien in a comp when he lost his kite. Andy was 115kg and I towed both of us back riding our boards back upwind to the beach easily.
Also towed a mate with a short rope of about 3-4 m at Augusta just for a laugh. It was great and worked well except for the transitions (have to loop it downwrds next time and go for a carve)

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Also towed a few surfers across the pass between Lano Island and North Point. They were doing it hard after a long day of surfing. Again got em on their feet and scurfing across the channel.
It's great fun but watch the extra load you put on your kite and lines.
Good winds,