Ron

Here's the diagram from PJR.

Chris

Yes, you need to attach at batten ends to tack. My sail has a webbing boltrope, and I've got webbing loops that are securely attached to both the batten ends and the boltrope, and they seem more than strong enough for sheeting.

Most junk sails I'm familiar with, and certainly the Hasler-McLeod standard sail do not have a sheetlet going either to the yard or the top batten, so a 7-panel sail has 6-point sheeting. I don't know enough about either multihulls or your sailplan to venture a good opinion on 4-point vs. 5-point sheeting.

The advantage of 4-point sheeting is simplicity, a shorter distance between the clew and the sheeting point (Dmin in PJR), while the advantage of 5-point sheeting would be better control over sail twist and ability to reef down to only one panel instead of two panels without needing to lash battens together or anything.

It sounds like your version of proa double sheets would be actually having two sets of what PJR calls single sheets, one lazy and led to the current bow....and hopefully not snagging badly while sailing. And you plan to be able to tack with the active one, at least for close quarters maneuvering. Is that correct?

I'm sure others have a lot more experience with sheeting variations than I do, but here's what I've found with Flutterby. My mainsail is a split sail, around 500 square feet, 7 panels, ~25% balance. I've got a single 3:1 sheet, with a block and a thimble on minimum-length 3-batten spans, and tried to fit it into a little less space than PJR recommends for that kind of span. With 5 panels, you would only need a 4-point sheeting system, simplifying things a bit.

Issues I've had have been battens hanging up sheetlets, and it was improved a little by putting bolts through my webbing boltrope loops and the sail and the batten end to stop the batten from protruding, and also by going from sheetlets attached to webbing loops (sewn to the sail and bolted to the batten) instead of tied to the battens.

I tried to draw the biggest sails I could fit given the mast and deck arrangements. I'm pretty sure if I had chosen to make smaller sails, not pushing the limits of what could possibly fit, some of the snagging issues would probably go away with more relaxed angles. If you have more space between your sail and your sheeting point, it should be easier.

The 3:1 sheet seemed to me to be a reasonable compromise between mechanical power and amount of string. I tried a 5:1 sheet on my mizzen and it was way too much string. I don't put it on a winch, but might want to in more extreme conditions.

Annie, thanks for giving me the short version of how to upload photos.  I have uploaded a few for your review. 

Thanks for your interest in Drua, and the link to Ontong Java which I had not seen before.  I am new to forums and will try to do a better job of interacting.  After 10 years operating Seabbatical our long term charter company, Drua was my attempt to make a more affordable, simple, better performing multihull. I love the simplicity of Proa's but need accommodation in both hulls like a catamaran.  A tacking only boat would have made things easier.  We wanted to be able to tack in a Chanel and shunt for longer passages.  Our rudders are in side hung cassets fore and aft on the long hull.  The rudder boards are able to be raised and lowered, and pulled forward for balance in either direction.  Both are hydraulically linked to one wheel.  I will try to get more photos of Drua on our website soon, or try to figure out how to add them here.

I have made my sails split to the top.  Each sail has 5 battens and a yard.  I have closed batten pockets on the Luff of the jib and leech of the main, and will lash the leech of the jib to the luff of the main to stretch the sail onto the battens.  For shunting, I will need double sheetlets, each sheeted to a block at opposite ends of the same hull.  They will be routed back to a block where the sheetlets attach to the main sheet and then to the cabin roof.  I am not sure how to do this yet.  And I am trying to decide if I should attach the sheetlets at the end of the battens or some distance forward?