I feel for you mate, spent the last 7 years not wave sailing because of a dodgy right ACL, partially torn. Nothing like going for a blast and feeling your right knee come apart and start slapping against the tibia.
I had the op (Peter Annear - brilliant surgeon) and had the new LARS graft, technically back on the water in 5 months but I took the long rehab and gradually built it up. Back playing all my sports and lost 10kg's because I can run again

I have a dodgy Achilles from years of hockey and have had some rehab on it, my physio says not to mess with it and treat it like a friend, rest when required and don't sail with it sore. She was adamant if I tore it I was looking at 12 months at least off the water.