I’ve read some amazing stuff in the Discourse group which has been immensely helpful in rigging our new/old boat, including stepping the mast. One thing I have not seen is how far from the boom end should the clew be lashed? Pics would be nice if anyone has them. Thanks
Ed NS 26u 1986
Puffin
Although there are some pictures and a mini-tutorial on lashing in the New Nonsuch Owners Quick Guide, on pp. 26-28 at the end of the section on rigging.
Log on with your membership email to www.Nonsuch.org, open the MEMBERS tabs, select MANUALS, and the Guide’s easy to find from there.
I don’t think there’s general guidance on how far from the boom end the clew should be lashed. It’s too dependent on the details of your specific set-up. It depends a lot on how your boat’s sail is cut and how much room your choker set-up gives you to move the boom forward and aft.
For example, the picture of a lashing on page 26, provided by Bill Wickett, shows a lashing that I’d guess might even be as much as 12-18 inches. In contrast, my own boat has it is as close to the boom end as I could get it and still have room to tie the needed knots.
I set it up that way because my sail is cut with a somewhat long foot, I have a lot of room to work with on my choker adjustment, and I want to keep the boom end as far aft as possible to avoid risk to tall cockpit occupants.
In general, you want to adjust it so that the sail can be flattened completely before the boom is prevented from moving further back by contacting the mast. However, you want it loose enough that, with the choker eased, the sail can puff out over the boom in light air.
You may have to experiment with it a bit before you’re satisfied, but it’s not hard to do so.
– Bob
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With all of the variations which have probably accumulated on our boats - tired sails or with different cuts or materials and who knows what else - I bet the answer is probably “it depends”.
On my boat the clew is shackled directly to the hole in the boom end. It came this way and I hadn’t actually thought much about it until recovering/re-rigging from all of the mast work last spring. So I’ve never seen a reason to change it. With the clew shackled directly to the boom end with a fairly short shackle, my boom hanger lines are approximately vertical when the sail is just barely touching the wishbone. Since those hanger lines are basically pendulums, this seems like the minimum stress position and also the position where it will have the maximum movement fore and aft. This, in turn, gives me the most range of choker adjustment in both directions.
I’m really beginning to appreciate the choker. A couple of weeks ago we found that we could go from a consistent 5kts to a consistent 5.7kts just by fiddling with the choker for a few minutes. (Slacking it.) And when we reversed it while passing Pt. Loma we lost about the same. I’ve been adjusting it in and out for a couple of years, but this is the first time the conditions were stable enough to actually quantify it. I was expecting maybe one or two tenths, not seven tenths. That’s more than 10%.
But like everything: I’m no expert, just maybe a little ahead of you in the learning curve.
Edit: Naturally Bob posted while I was writing this. I haven’t read it yet, but he’s probably right! 
Second edit: Yup, I told you: “it depends”. 
Thanks y’all. I appreciate your input. Just another thing to experiment with when we sail Puffin home.
Ed
Although I’m a beginning Nonsucher, I have a slightly different view on this topic — one that includes a specific rule I’ve found very practical.
The rule came from what I believe is a necessity: being able to pull the wishbone tight against the mast when motoring in confused seas. It also helps prevent unnecessary damage — especially in situations where the choker line is pulled in too tight. With the boom already snug against the mast, there’s simply no way to overtension the clew or overload the track.
Here’s the rule:
Make the lashing between boom and clew just long enough so the foot of the sail becomes properly tensioned at the exact moment the mast “kisses” the bumpers on the inside of the wishbone. No more. No less.
This setup gives you:
a flat and well-tensioned foot under sail;
a boom that won’t swing wildly when not sailing;
a physical limit that protects hardware from overloading.
It’s a simple, repeatable reference point — and it works well for me.
Curious to hear if others have tried something similar.
mark-h
n36#25 Cotton Eye Joe
netherlands, europe
Your rule makes a lot of sense to me Mark. I’ll have to try it out. I currently have my lashing much tighter than that. I’ll probably have to get a longer line.
Ed
These do seem like good objectives. I bet Bob N. appreciates that last point right now. I rarely motor more than short distances, but I’m going to look at how my setup compares. And I’ll admit that it never occurred to me to choke the boom back until it is hard against the mast (if I even can) to prevent boom bounce during the few times I have motored very far. Hopefully you’ve just given me a new tool to use!
But I do have a couple of questions about it. A boat is never at rest. So do you slack the choker when you are tied up? Because constant contact - even with the vinyl boom cushions - will abrade your paint and eventually your aluminum mast. Even for long spells of motoring it seems like the paint is going to disappear pretty quickly due to chafing. Have you seen this problem? Do you have some sort of chafe protection?
Given my current problems[1], yes, physical limits to prevent hardware for over-tightening does sound like a great idea.
In addition to the points that Brian raised, though, I have two additional concerns with your suggestion, Mark:
- How feasible is it to get – and keep – the maximum sail tautness and the stop point of the mast choker exactly coordinated? If you err in one direction, you’re giving up the ability to get the sail as flat as you may need it. If you err in the other direction, you’re risking over-tightening and doing damaging in the course of setting it up.
- If you’re doing a lot of motoring, or storing the sail that way while not in use, couldn’t this lead to a lot of extra stretching to the sail and accelerate loss of shape over time?
For avoiding overtightening, a good discipline (although admittedly one I forgot) is simply to not pull the choker more than hand-tight when the sail is down.
On my friend’s N36, he’d always followed the approach you suggested, Mark. One time we weren’t quite sure the mast was all the way against the boom. So, we put the choker on the winch then, too. Rigging the sail clew so that the boom was stopped by the mast did indeed protect the sail track from getting pulled out. Instead, we broke a block on the choker tackle. (And, when we repaired that, also discovered a lot of chafe on lines that’d been trapped between the mast and boom.)
With that in mind, what I’d say the lessons are comes down to:
-
lash the sail so tightening the choker takes the boom close to the mast, but don’t worry about getting it perfect
-
if you’re going to be motoring with sails down in heavy conditions, tighten the sail hand-tight, and find some way to counter the boom’s side-to-side swing with downward preventers to avoid chafe against the mast. Two alternatives that occur to me are:
(a) use a small weight to toss a line over the boom on each side, then secure the line ends to side cleats; or (b) pull the reefing lines tight so that those lines are pulling on the boom as downward counterforces to the boom hangers. -
Whatever you do, don’t use winches to tighten running rigging when the sail’s down.
This all makes it sound complicated and risky, perhaps. The important thing to remember is that we’ve got pretty well-made, pretty forgiving boats. My friend Phil had been keeping his boat set up that way for 17 years before his problem occurred, for example.
– Bob
For those not following the other thread, I made the mistake of going for a taut look on the sail cover by putting the choker on a winch with the sail down. The result was that forces intended to be distributed over 40+ feet of mast track were concentrated entirely on the bottom 2 feet of track. This pulled about 28 inches of track off the mast. ↩︎
Bob, thanks again for engaging in this — your experience adds a lot to the discussion, and I really appreciate you taking the time to write it all out.
Let me try to clarify what I meant in my original post, because I may not have explained the reasoning behind it clearly enough.
This thread started out with a question about the clew-to-boom lashing, and while it might have seemed like a minor thing at first, I’ve come to feel it’s actually one of the more underestimated details of the Nonsuch rig. It’s not flashy, but it has a big influence on both sail performance and rig longevity — at least in my experience.
How I’ve approached it
What I try to do is lash the clew to the boom just long enough so that the foot of the sail becomes fully tensioned right at the moment the wishbone bumpers touch the mast. That “kiss” acts as a kind of physical limit — not something that happens during normal sailing, but something that prevents accidental overstretching if someone hauls a little too hard.
In practice:
- While sailing, the boom stays well aft of the mast. The sail forms its airfoil shape, and there’s still plenty of room for trimming.
- At rest, I leave the choker slack so the boom can hang free. In calm harbors, it doesn’t touch anything.
- When motoring into chop, I’ll snug the choker just enough to keep the boom from swinging around. I feel this causes far less wear than a boom that’s free to slam — especially since I have a carbon mast and boom, which aren’t very forgiving to shock loads.
This setup has worked well for me. It gives me confidence that I can trim the sail without damaging anything, and that nothing will get overloaded by accident. Once it’s dialed in, it becomes a reliable reference point.
On “getting it perfect”
You mentioned not worrying too much about precision in the lashing length — and I get where you’re coming from. But for me, that particular adjustment turned out to be worth spending time on. Once I got it right, it removed a lot of uncertainty when setting up the sail. I don’t think of it as perfectionism — just a small setup job that pays off repeatedly.
And personally, I’ve found that discipline alone isn’t always enough — especially when I’m motoring through a narrow inlet with short, steep seas. In that kind of situation, I don’t want to rely on judgment or feel. I want the rig to already be set up in a way that avoids problems. On the N36, the choker often goes to a winch, so “hand-tight” can be a bit of an ambiguous term. I’ve found that having a physical stop — defined by the clew lashing, not the choker — helps avoid trouble.
About alternatives
Your idea of tossing weighted lines over the boom (idea a) might be workable in calm conditions, but I’d find it tricky to do safely at sea. And using reefing lines as boom checks (idea b) makes me a little uneasy — just because I’d worry about transferring loads into the sail or track through the reefing hardware. Maybe that’s overly cautious, but it’s something I try to avoid.
Final thoughts
What I’ve come to realize is that this small bit of rigging — the clew-to-boom lashing — ends up having a big impact on how the whole system behaves. For me, taking the time to get it just right has helped with:
- sail shape when under way
- boom stability when motoring
- and protecting the gear from overload, especially when the sail isn’t up
I used to assume this was just “how you rig a Nonsuch,” but I’m seeing now that people do it in different ways — and that’s part of what makes this forum so useful. Thanks again for sharing your experience, and I hope more owners weigh in with what’s worked (or hasn’t) for them.
– mark-h
This is one of many topics for which there are many good answers, but probably no single “right” answer.
A lot depends on how the boat’s to be used. I make very different use daysailing my 26 in calm Southern California waters where a gale is a once every few years event, than someone might make cruising a 36 in much more challenging conditions.
I strongly agree with the idea of trying to rig our boats so that physical stops rather than mental discipline are the primary means of protecting against damage.
– Bob
In my case I don’t seem to have any choice but to lash the clew as far as aft as I can, right against the fitting on the end of the wishboom. The foot of the sail is too long to do otherwise, and it seems to me that if I did I would not be able to get the full benefit of the choker in flattening the sail. I note too that the sail diagram on page 41.2 of the 22 manual seems to show the clew in this position, for what that’s worth.
Rather than lashing, I simply used a soft shackle. Installed it on clew before attaching sail to mast. Easy to do, and easy to remove at end of the sailing season.
Don
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Yep, that definitely works, too. You can’t adjust the clew distance from the boom end, since the shackle’s going to be a fixed length, but soft shackles are really easy to make. So once you know what you want, there you are.
– Bob
Going back to part of this discussion where we discussed trying to rig the sail so that you could lock the boom against the mast…
This was taken on a Nonsuch 36 that I helped repair last year, but I only just now found the picture.
It illustrates what can go wrong if the boom is pulled against the mast to a point where it locks against it. The seriously abraded choker adjustment line just above middle center in the picture is the result of chafing from the port boom rubrail being pulled in contact with it. The cover’s completely gone and, if you look closely, you can see the start of fraying in the core as well.
This may not apply to all boats, since there’s variation from boat to boat in exactly where their lines run. But for those considering locking the boom against the mast, it’s worth checking if there’s any similar risk on your boats.
– Bob
Concerning the boom rub rail chafing the chocker line when contacting the mast, perhaps the boom hanger lines could be shortened a couple inches to prevent that happening.
Brian
Not sure.
I’m not good at visualizing or sketching the effect of changing the hanger line length.
Since the line in question is what’s pulling the boom toward the mast, it’s going to be pulling the boom toward itself. I’ve got two questions about what’d happen with changing the hanger line lengths:
- Since the control line’s pulling the boom toward itself, is there a risk it could still get caught?
- I think (but am not sure) that the idea is for the control line to be level with the boom front end. The reason I’m guessing this is that, in my limited intuition, being in line would maximize the effectiveness of tightening the control line. Being above or below would pit the control line against the weight of the boom.
But this is a bit beyond the borders of my limited rigging expertise.
Other folks’ thoughts?
– Bob
Yes upon further reflection after your comment Bob I can see that raising the fulcrum point(the hanger length) pulling on the choker would tend to put upward force on the tail end of the boom. So perhaps extending the hanger line length would be a better solution because it would put downward force on the tail end. That could be done very easily by adding soft shackles to the hanger line length. However, minimal the force may be it would still contribute to flattening the sail which is the whole purpose of choking. However, by the picture I can see that there’s not a lot of space between where it is and the line entering the mast.
Brian
Hi Bob,
You told us that your friend Phil had been keeping his boat set up that way for 17 years before his problem occurred. Does that mean that the choker line was 17 years old?
My mast, wishbone has the choker line rigged like this
Mark,
Running rigging had been replaced, so the damaged line in the picture I posted was at most four years old.
Your rig looks completely safe from any chafing problems. I’m curious how hard it is to pull in towards the end. It’d seem like the closer the front of the boom comes to the mast, the more the choker is pulling downwards rather than aft.
Does the boom swing enough on the hanger lines that it’s not a problem, or does it get very difficult to do the last bit of tightening?
– Bob
Bob,
The angle in which the picture was taken doesn’t do it justice. Here’s another one:
Note how the choker line is pushing the wishbone boom towards the clew, rather than pulling it straight back horizontally. I would think that’s the ideal angle for flattening the sail.
I don’t experience any issues tightening the choker. I should mention that when I ordered my new mainsail, I redesigned so that the boom needs to be lifted slightly for the first reef, and even higher for the second. I did that intentionally—I don’t want the boom hitting the water when the waves get bigger.
As the boom goes up, the choker line (and especially the choker hardware) stays clear of the boom.
Also worth mentioning: I haven’t altered the length of the hangers or changed any of the wishbone/choker points. This Nonsuch has been set up this way since 2008, when the rig was replaced. The mast was built by the same folks who made yours. My mast track is also glued on—but not with epoxy! They used 5200 on mine. Interesting, isn’t it?