Hey Tom,

Definitely, one of those things I should have done long before, I think they're great... Couple of caveats, however - my main is quite the opposite of yours, extremely high aspect, and full-battened all the way... But here's my thoughts...

First, I highly recommend going with Amsteel, or a similar spectra line, great stuff for this application, and will eliminate the need for any blocks (except for at the spreaders, perhaps) in the system... Dead simple to splice, will result in a very 'clean' setup, will create minimal chafe, and the rope easliy slides through an eye splice or a thimble... And of course, it's the strongest, lowest-stretch line out there, so you can go with a very small size, 3/16" would probably be more than adequate for you...

I don't see the point of lazy jacks without making them retractable, and stowable at the mast... eliminate the potential for chafe, and the problems they can create when deployed with fitting a conventional mainsail cover - especially one like mine, which is more of a 'drape' over the sail, and hangs well below the boom... And of course, you can get them out of the way completely when hoisting the sail, eliminating the batten 'hang-ups' that plague so many of the fixed systems I've used...

But Dan Y has already mentioned one of the most essential features, that make mine work for me... Namely, tops are not attached to the mast, but rather the spreaders about 18 inches outboard of the mast track... This is a big improvement, IMHO - allows you to usually hoist the sail without catching the jacks if you want to, and eliminates the potential for mast slapping in a breeze when they're stowed...

With a single spreader rig like you and I have, that gives you all the height you need, these things really only come into play as the bunt of the sail gets pretty low to the boom, anyway... One thing all the systems I've had to deal with that were troublesome seemed to have in common, was that the attachment at the mast might have been too high... Although with a low aspect main like yours, you definitely need a bit more height than I do, but to my eye your diagram looks fine, and I'm sure going to the height of your spreaders would work fine...

You'll want to fiddle quite a bit with getting the attachment points on the boom properly positioned after the sail is flaked, that's probably a bit easier to do with full battens, they really help define where the legs need to be...

Good luck, you'll be very happy with adding them, I'll bet...

best regards,

Jon