| 670 ww and 450 lw

I thought so.
So both of those are much thinner than our rough 3' hull width guess.
If we assume a 12' trailerable has the hull widths of the Ex40F, that suggests we could have ~8.3’ (+ ~2’ lee hull) x ~20’ of ww cabin width to work with. If needed, we can add another ~1.5' of width if we wanna go over/notch the lee hull.

Just a guess, but adding 3½’ (or ~5’) x 20' of cabin width to the Ex40F would make rather generous accommodations? I do not have a good eye for this. What do you all think?

Also, we have more space under the cabin hull, so we can have the steps down to ww in the cabin like the Ex40 does, and still have the under cabin tender for trailering and marniaing

Ok, back to sails.

| > | > | But rotating booms might be tough with wishbone booms.

| > | > why is it hard for the wishbone, or half wishbone to rotate around a fixed mast?

| > | Because it is usually only attached with a single string, id the mast doesn't rotate, the attachment point on the mast needs to move as the sail does. This can be arranged using a strap, but adds complexity when the sail is raised, reefed and lowered.

I wanna come back to this Rob. I skipped over stuff. What parts are more complex, just the boom strap, or other parts too?

Also, what you mean by complexity?
Is the strap more complicated to make, or operate/maintain, or what? Could you dump more detail here please?

If a strap is more complicated, than a string, but less so than than a rotating mast/trucks, that's an important distinction. I wanna understand the options and risks. So, can your answers paint some context.

| > Is there more complexity/cost/reduced robustness/failure modes in rotating masts, or rotating booms? And/Or, what do I/We need to know about this to pick a solution for a boat?

| Both are pretty robust. Masts are more expensive to set up and bearing alignment is critical.

What is the expense to setting up rotating masts?

How hard is it to get bearing alignment right?

| Tracks, cars and bearings are expensive. The main thing you/we need to know is whether the tied on sail solution is better aerodynamically, and, if it isn't, whether the lower cost is worth the lower performance.

To be clear, rotating masts, specifically, are more expensive to set up? Or are all masts?
Language question; What is a mast without expected accoutrement called vs kitted out masts? Or are they both just masts and the accessories are more about the rigging?

Please clarify your recommendation of rotating booms vs non rotation booms and rotating masts. With why, also, please.

| All the evidence is that it is better, but there have been no full size tests apart from the ones on Bucket List which were promising, but with nothing to compare against, not much help.

| Most/all the potential problems with handling the tied on sail have been sorted, but again, not all have been tested full size.

I recognize it is an experimental rig. Of line you and I have talked about this rig. I am in. I want to help figgure this out.

My thinking is, if the aerodynamic performance is not great, but the sail area is cheap and can be voluminous, then, unless educated otherwise, I think I would choose that. Why shouldn't I?

If, it might have poorish performance, but it may be great performance, I think I want to fiddle with it, under your advisement, to figure it out/help refine it.

If it turns out great, then great! Right? Or did I miss something?

I mean I was looking at a junk rig anyway, simply for the value of the sail..

| > If you think it interesting, I would love to know more about how this all works.
| >
| Easiest is if you ask questions, which I will answer.

This assumes I know anything about masts and sails!
Well perhaps a learned reader will jump in, and help me ask smart questions..

| The fundamental point is that the turbulence behind a mast/sail is far worse on the lee side than the windward one. So a sail against the lee side of the mast works better. Attaching it is the problem. A track on the lee side of the mast works, until you are caught aback, when it gets ripped off. Strings work, if they are tight. Hoops are easier, but not tight, particularly on a tapered mast. A string on them will pull them tight, but needs to be accurately tied, and changed when you reef.

| An endless line tieing the sails to the masts gets messy when the sail is lowered and the sail tends to blow away when lowered. So individual ties are required, with some means of tightening them, which is not difficult.

So, are you saying you think you got a good set of solutions for holding the sail against the lee of the mast? And it can flip 'from aide to side', when you shunt, for example?
And it is easy to tighten/loosen, and plays well when disassembled/re-assembled?

| The next issue is attaching the halyard, downhaul and boom so the sail can be raised and lowered. Ideally with a simple, fail safe halyard lock so the luff tension does not change when the mast bends. We have solutions for these, but I suspect there are others.

Ok, so you are reasonably confident you got a plan for your super cheap sails to work, and you think they will also be good performing.

I am in. I wish I knew enough about sails to engage you further. I don't.

I think there was a video of a halyard lock by Mr Aitken. Is that similar to your idea Rob?