I have one of Synthia's excellent spinnaker nets and used it in the 2006 SHTP. If you slack the jib sheets (red in my photo) and tie them down forward, you can hoist the spinnaker net over the furled jib - the loops are large enough.* But for my boat, I decided an over-sheeted blade (jib) had the same effect, and it also helped get the bow back down in a broach. I later bought a proper spinnaker stays'l and run it on a little Karver furler.
Hell hath no fury like a sock, spinnaker net and kite all hopelessly twisted together up high where you can't reach it. To quote Rob, "ask me how I know this."
*Yes, you'd need another halyard. Rags has two jib halyards (the lower one is used as a topping lift) and two spinny halyards.
As our readers can tell, there's no end to this stuff. Get a 40 year-old Olson 30 or Moore 24, keep it simple, practice a lot and go beat everybody. It's been the recipe for years.
Before I head to the boat I wanted to add a tidbit: There are few sailors better at racing a small boat than Melinda and Bill Erkelens, yet for the very windy Double-Damned (Columbia River) they used a spinnaker sock on their Wylie Wabbit. Very nice for gybing (etc.) in 35-knot gusts. I plan to use mine more, now that I've resolved some issues with it. (Teaser: One help with a sprit is running the dousing lines OVER the center pulpit bar...)
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