Charlie -
I don't actually own a J/30 yet, so a little cart-before-the-horse. I am under contract with one though, that will need a new main.
I'll be almost exclusively PHRF racing as there aren't any fleets here in Maine. However, there are a number of J/30s (a couple newly arrived) so perhaps we'll get the ball rolling.
The mainsail will be kept on the boom. I rolled the membrane sails on my last boat for awhile but gave up when I determined I was causing more damage by rolling and subsequently folding to get below (no structural tube in the roll). With out using a shackle for the clew, the sail gets mangled running the foot down the track. I've found easing the outhaul and doing big loose flakes with a horse-blanket cover is the least damaging, in my situation anyway. Alternatively using horizontal battens and doing a 2/3 roll with storage on the boom is effective (though the sail ties end up heavily loaded keeping the roll stable). We did this method on a Farr 40 program I crewed for.
Why do you say flogging will happen during day sailing vs. racing? That's not the case for any of the boats I've been involved with. The sound of flogging is a sail makers money maker.
