Part 1
The tragedy on the CNB 66 Escape, in which Volker-Karl Frank and Annamarie Auer-Frank were fatally injured while attempting to shorten sail in a gale with in-boom roller reefing, got me motivated to take a deep dive into the benefits and drawbacks of each of the three primary options for mainsail handling.
Before writing, I:
- Read through many comments from owners of both automated systems and slab reefing.
- Interviewed my friend Hans who has owned and done challenging ocean passages with all three systems.
- Went out with Hans on his Far 56 Pilothouse Cutter for a demo of his in-boom system and produced a video.
- Had a very interesting email exchange with John Kretschmer, (John-K) who has slab reefing on his beloved Quetzal, but has done a trans-Pacific (California to Hawaii) and five East Coast to Caribbean voyages with in-boom systems, and even made some illustrative videos for Forespar/Leisurefurl in the past.
- Over the years, talked to many other owners of all three systems.
I also have personal experience with both automated systems, albeit limited, and, of course, some 50 years of using slab reefing offshore while racing and cruising on all kinds of different boats, ranging in size from a Sea Sprite 23 up to our previous boat, a McCurdy and Rhodes 56.
Rank By Criteria
Analyzing the advantages and disadvantages of each system turns out to be surprisingly complicated, so to simplify things let’s use the following criteria to rank each system on a scale from one to five, with five being the best in that criterion:
- Convenient to use
- Low physical demands
- Low skill required to use
- High reliability
- Easy to repair
- Fault tolerant
- Good sailing performance
- Reasonable cost
- Low risk and safe to use
Personal Needs and Wants
Of course, the problem with any scoring system like this is that we all have different needs and wants. For example, I might put safety first, another person cost, and a third person performance—all are valid ways to look at this, as long as we are realistic about the downsides of each option.
So I have also created a spreadsheet where each of us can weight the above criteria, much as I did with anchor selection.
To make this weighting easier, I have included my thoughts on factors that affect weighting at the end of each criterion.
I also assumed that each system is best-in-class designed, engineered and installed, since it’s stupid to reject a system and buy a different one just because the incumbent was a poor example of its type.
The whole idea here is for each of us to come up with the system that’s best for us, rather than turning this into the bullshit of “mine is best” so typical on forums and YouTube.
Let’s do it:
Is there much variety between the three systems’ ability to enable reefing downwind, or is that determined more by other factors like spreader angle?
HI PD,
Short answer, a lot of variety. Long answer under safety in part two. In the mean time you may want to read my analysis of the tragedy on Escape and also view the video I did with Hans since we cover a lot on the subject of reefing downwind. Spreader angle has little effect on reefing down wind, when set up right.
Adding a storm trysail on a boat with in-boom furling, could move the Fault Tolerance score from 1 to 2, or even 3 if the trysail has it’s own track and halyard.
That would be the same for in-mast furling.
On my 30 year old Selden in-mast furling setup the mast extrusion has an additional luff groove for a storm trysail or spare main.
In an emergency even a foresail with rope luff could be hoisted, if I can trust the docs.. 🙂
Hi Arne,
Sure, those were example, but there are other ways to logically adjust, although in my opinion to take the score adjustment you would need to actually have the storm trysail and have it rigged and ready to go at all times when at sea and have tested it.
Have you ever tried to hoist a foresail into a grove in anything above 15 or 20 knots of wind, offshore? Well I did and I promise you that only works when you have two more experienced and strong crew members available.
If you compare likes with likes then I don’t think that the physical demands of slab reefing with a powered winch for the halyard and separate leech and luff reefing lines is any more physically demanding than the alternatives.
But I am biased – to me roller systems are a brilliant solution to a non-existing problem.
We have sailed Roundabout II about 25,000 offshore miles with Selden mast furling. I go up the mast regularly to grease the bearings and have just replaced the Lewmar deck line organizers with Selden. I regularly reef and furl off the wind without using electric winches. Provided attention is paid to reducing friction a moderately fit man or woman should not need powered winches. My wife will use the winch to furl in stronger winds, I am able to simply able to pull the lines in.
Our boat is a Moody 40 which is small by comparison to many we see out cruising. We bought that size because we do not want nor trust electric winches. We have seen some horrific malfunctions leading the loss of fingers and a forearm in one case.
We consider that in mast furling is safe and convenient requiring only the it be maintained properly.
Hi Ted,
Good to hear that your in-mast system can be used without an electric winch. Is the roller furler itself electric or manual? I’m guessing not from your comment, but want to verify that.
Also, I too am nervous about electric inches which is one of the reasons that we never fitted them to our 56 Foot McCurdy and Rhodes. One of the reasons that worked is she is rigged as a cutter.
We also have a trysail on a separate track for redundancy. So far have never need to use it
Ted – Roundabout II
Hi Ted,
That sounds good. A trysail is one of those things that most no one cares about until they need it. Having used one once I love them!
What about those behind-the-mast furlers? Ugly, and probably smacks the mast at anchor, but it seems to me that if you want ease of use it’d be hard to beat.
Hi Michael,
If I wanted to have some alternative to slab reefing, that would be the only option I could live with. It also has the benefit that it gives a bit less load on the mast tube, as it only gives compression, no mid section side loads. I don’t really think it’s any uglier than a roller furling head sail.
That said, I’m also not in love with roller furling head sails. The simplest, cheapest and most reliable there is, is hank on sails. That’s off topic here, so I won’t elaborate.
You’re missing the support a reefed (slab) mainsail gives to the mast section.
Hi Douwe,
I would also never choose anything but slab reefing, so we’re on the same page. What I was aiming at here was only that a behind the mast furler is just as reliable as a furling headsail, which is also not perfect, while an in mast furler is dramatically more vulnerable.
It’s true that a reefed main that is attached along the mast can give support to the mast tube. However, support is mainly needed to counter the uneven loads from that very sail, like when it flaps, etc. The problematic loads from a deeply reefed main on the mast are dramatically bigger than the support the same sail gives. One of the reasons a cutter rig is good for ocean sailing, is that the cutter stay helps with these loads. A behind the mast furler gives no such load on the mast.
Either way, my choice is slab reefing. No doubt.
Hi Michael,
I have a side bar on them on part 2.
Hi John,
I have a hunch 🙂 that, after these articles, your preference will still be slab reefing. I’m probably more prejudiced than you. I try to keep an open mind about these alternative “comfortable” systems, but so far I totally fail to see their benefits. In my mind, using the mast or boom as sail cover is just silly.
That’s the only benefit I can see they have. I’m convinced that I can both hoist and lower the main, as well as reef, on average quicker with a good slab system than any of the other systems. Taking in a reef on our 40 foot cat (equivalent loads to at least a 50 foot mono) takes less than a minute upwind and less than two minutes downwind in a blow, when I do it alone. We have no fancy systems. All manual and simple. I have strong arms, but even when that diminishes (62 y.o. now), simple adaptions and a bit more time will be plenty remedy to keep me sailing.
I can see that in the right conditions, your ratings here are not wrong, even though you probably intentionally give the mentioned systems a bit of a positive skew. That way, the coming inevitable conclusions can’t be criticised for unfairness. I applaud that.
My view, so far, remains:
– I will never, no matter what circumstances, consider in mast or in boom furling, as they give me zero benefits and very important disadvantages.
– The reason these systems get gradually more prevalent is that the sellers promote them, because it gives them greatly increased profitability. They make far more from the extras than from the basic boat sale. This creates a false market for “upgrades” that in my mind are close to scams.
My dislike for these systems often finds little resonance with other sailors, as people tend to defend what they have with strong emotions. Still, I’m always right, so I don’t worry. 😀
fair assessment
(except for you being always right 😉 , of course)
Hi Stein,
You are right on the speed issue. I timed Hans’s demos and in most cases I could do it faster on the McCurdy and Rhodes by myself and a lot faster with Phyllis’ help. That said, Hans was a bit faster taking in reef and shaking one out than I would have been doing the same on slab. But once you take into account starting the engine and rounding up, I would have been close, or maybe a bit faster.
Anyway, this is not about what I would choose. I made that call years ago when we replaced the mast on the McCurdy and Rhodes due to some cracking in the old spar. A lot of people thought I needed my head read for not going in-boom or in-mast.
So the idea here is that people making the decision with an open mind will have an analytical framework to work with to pick the system that’s best for them. I’m also hoping that this series will help protect those new to offshore sailing from at least some of the worst of the salesman BS out there. It’s fine for someone to pick in-boom because that works for them, but it’s not fine for some salesman to convince them that in-boom is safer and easier.
People do tend to defend what they have or what they are used to. Being used to slab reefing, I viewed in-mast as a negative when we evaluated our current boat, which otherwise fit our needs well. Now that we have it and are used to it I see a lot to like. John’s article hits the tradeoffs well.
It seems silly to say there are no benefits. It is faster to set, reef, and take in. We sail more on short passages or in marginal conditions, because it is so easy, we are not hung up on whether it was “worth it” to set the main. It seems more reasonable to weigh the benefits against the downsides, and the cost/hassle of making a change.
If our boat had slab reefing, I would happily use that system and not change it. I would probably choose slab reefing over in-mast if I was starting from scratch, but I’m not so certain now after using the system as I would have been without that experience. And I have become convinced that used and maintained properly, in-mast is a reliable and seaworthy system. It seems to me that the most important thing is to know and understand your system well and get experience with it in a variety of conditions.
I terrsting that nobody discusses the issue of inmast furling jamming versus inboom when you can still lower the mainsail and flake over the boom. This weekend have just used a Leisurefurl inboom here in Greece versus my Mainfurl boom and both have advantages, although the Mainfurl is better suited to a self tacking jib. IMHO.
Hi Rod,
I cover that in part 2, which we will publish in a few days.
i often am not in complete agreement with John but this time I completely agree. Having owned a Swan 46 (slab) reefing, rather complicated since the 15winches were spread all over the deck, mast and boom. A Hallberg Rassy 53 with hydraulic in mast furling, never had so many jams in the mainsail until we replaced the entire mainsail with a new one that when handled with care never failed to unfurl or furl. The only one on board allowed to reef was myself by the way which underlines your observation. The next owner waisted the only two year old (15K) Hydranet mainsail within two weeks of ownership. When we build our Dijkstra 56 I specified slab reefing, Two lines per reef all led back to the cockpit (electric) winches, Never an issue, also the new owner never had issues with this system. On the Gallant 53 (1968) I have slab reefing at the mast, although a bit wet sometimes never problems. We are now sailing a new to us Bestevaer 53 with single line slabreefing managed from the cockpit. I had hesitations with single line reefing due to earlier experiences on a delivery of a Bestewind 50. Initially there was way to much resistance in the single line system but after replacing the reefing lines (and clutches) with slicker and thinner lines (Gleistein dyneema) it works remarkably well. My wife and just crossed the Bay of Biskay in winds going from 15 to 40plus, we had to put in reef 1,2 and 3. We never had to go into the wind to take the pressure out of the main and effortlessly reefed the main. It’s really important to mark the reefing lines and the halyard to be able to do this right first time, especially at night time.The downside is the very long tail ends of the reefing lines but the Bestevaer has a huge amount of space for that in the cockpit.
you didn’t take single reefing into account but when well set up it might make things easier for a small crew.
After sailing Asia, the Medd, and now the (eastern) Caribb over the past 22 years, with just 2 of us on our Taswell 43 monohull, our vote is solidly in the in-mast camp. We did have an issue with our in-mast furler….turned out the upper swivel had 3 sets of bearings in it, and 2 of the 3 sets froze. It occurred, and was repaired, when we were in Athens, Greece, in 2012…and we have had “0” issues with it since. The ease of sail handling, the lack of pulling the M/S up, especially since we’re cruisers, not racers, the (slightly) smaller M/S-no roach-and the lack of battens has minimal impact for us. Our previous boat, a TaChou 33, had slab reefing-what a PITA! And yes, we have a separate parallel track for a Trysail if we should ever need it-we haven’t yet-we just reef in the M/S as we need to.
And can you reef off the wind?
I would like to share our experience from 15 years sailing a Sabre 452 (45’) with slab reefing. The mainsail is a heavy-duty Dacron cruising sail made by North Sails for the 2000 season, on an Anatal mast track, fully-battened with Shaefer’s Battslide System batten receptacles, and with a Dutchman sail flaking system with three control lines. Obviously, one cannot put a fully-battened mainsail on an in-mast or in-boom furling system. The Dutchman sail flaking system has exceeded all our expectations, possibly because we have been blessed to have had it installed perfectly, and we adjust the control lines as needed. I believe a 45’ boat may be ideal for this system.
In an emergency one can dump the mainsail in an instant by simply releasing the halyard (no matter what the point of sail), and then center the main sheet. The mainsail flakes neatly on the boom.
Slab reefing is similarly convenient: ease the halyard, go forward to attach the ring to the horn, tension the halyard and take in the reefing line. To hoist, I jump the halyard at the mast and my wife takes in the slack in the clutch (companionway). I wax the Anatal mast track twice a season, and the benefit is amazing. As John stated, use-it-or-lose-it. Personally, I enjoy the exercise benefit from jumping the halyard and even climbing the mast (ATN mast climber) a few times a season to inspect the rig.
I rate this setup: Convenient to use 4, Low physical demands 2 (I like exercise), Low skill required to use 5, High reliability 5, Easy to repair 5, Fault tolerant 5, Good sailing performance 5, Reasonable cost 3 (more expensive mainsail design and hardware – Anatal track and Shaefer’s Battslides), Low risk and safe to use 5.
In summary, the ideal solution for any sailboat depends on so many personal considerations, and I am unqualified to comment on in-mast and in-boom furling systems. Rather, I simply wish to share our experience and suggest additional considerations in case someone finds this beneficial.
Hi Ian,
Thanks for making the point that the key to slab is that it be well thought out and that once that’s in place, all is good. I have never used the Dutchman but always thought it looked a bit complicated and fragile compared to lazyjacks, but clearly you have made it work well. Have you done any ocean passages with the Dutchman? I have always wondered how the system would hold up against days on end at sea.
Hi all,
I am curious, with regard to in-mast roller furling of the mainsail, how all that weight aloft affects the boat at anchor. There is the sail, the gear, and, I would think, a weightier extrusion to handle the large hole to accommodate the sail and remain strong.
I would also think, but have not heard mentioned, that designers would have to design a taller mast (more sail area) to achieve the same horsepower to make up for the loss of roach and the efficiency that battens provide.
Thanks for your thoughts, Dick Stevenson, s/v Alchemy
Hi Dick,
Not sure it would make any difference at anchor, but yes weight is a big issue with in-mast. I address that and relative performance in Part 2.
The in-mast system is heavier in total, and has a higher centre of gravity when furled. Thus, the boat’s overall centre of mass is higher and its roll and pitch moments of inertia are larger.
All else being equal, then, an anchored boat with an in-mast furler will have a slower roll period and a larger roll amplitude than you would experience on the same boat with an in-boom furler or a slab reefing system.
And yes, if a yacht designer is considering a hollow-roach sail, then they must either accept some loss of power or increase the P dimension (and therefore the mast height) in comparison to what would be required with a straight-roach or positive-roach sail. (I assume John will address this further in part 2.)
Hopefully not front-running part 2, but might it be better in at least some cases to mitigate the loss of main power by increasing the E (foot) dimension vs P?
Hi Steve,
Sure, that’s an option. However, one problem with increasing E is added weather helm, which many boats suffer from already. Also means a new boom and a new mast, so a lot more bucks. More in Part 2
Hi John,
I see why a longer foot would require a new boom, but not yet why a new mast would be needed… I expect I’ll understand after reading part 2! Thanks for digging into the details.
Steve
Hi Matt,
Thanks for your thoughts. So, if I read you correctly, it sounds like there would be a difference at anchor, but not that the difference would appreciably affect comfort.
I would be interested (in the next article perhaps) in the percentage increase in mast height to match horsepower. I met someone a good while back who opted for conventional main design over in-mast because he knew he would be on and around the ICW where mast height is limited to its 65-foot bridges. If I remember accurately he calculated 10-12% increased height would be needed taking into account both sail size differences and the decrease in efficiency of no battens etc. that affects shape and horsepower generated.
My best, Dick Stevenson, s/v Alchemy
PS. Speaking of comfort, can those with roller furling in-mast speak to how easy it is to keep their rig quiet at anchor (or in marinas). This is a what some would call a pet peeve of mine: I hate noises at night.
Hi Dick,
At anchor, in-mast doesn’t seem any different on the noise front than slab. Just need to make sure the halyards can’t bang against the mast. However, I’ve heard that the mast can “whistle” if docked with the wind on the beam; the gap in the mast acting like a flute or the top of an empty bottle.
We actually haven’t experienced this, perhaps since we are mostly anchored or moored. We do have a flute stopper you can run up the gap to fill it and stop the whistling, but haven’t used it, so can’t speak to its effectiveness. The theory seems sound.
-Raj
Hi Raj, Dick
When we were spending time in Antigua quite a few years ago, big yachts at the marina with in mast furling were emitting unearthly howls at various pitches as the trade wind played across the slots in their masts. Very spooky. I recall someone saying that closing the slot with a fabric cover was fairly simple but it certainly was not standard practice in those days!
Wilson
Hi Raj and Wilson,
Thanks for the feedback. I was thinking more of the internal equipment making noise and hard to quiet, but I suspect the sail wrapped in there dampens the sound a lot.
As for the “howling”, I would not have guessed at that, but I suspect that may explain a spooky sound I heard at zero-dark-thirty one night in a marina and wondered what it was without the slightest inclination to explore and find out.
My best, Dick
During hurricane Irene in 2011, the fabric tape that closed the mast slot of a boat at the dock off my stern at Northwest Creek Marina in New Bern, NC popped out of its slot during the storm and streamed from the masthead like a long pennant. It entangled with the mast of the boat in its portside slip, and as the storm continued the tangle grew drawing the two masts together at their tops. Many of the expensive bits up there were damaged.
Hi Dick,
Given the weight of in mast systems, increasing mast height would do little since so doing would make the boat much more tender, and could even make her unsafe, since the added weight is all so far from the centre of gravity. More in Part 2
Hi John, Interesting: a trade-off clearly. I look forward to part 2.
Hi Dick,
I recall from my days living and working in a marina that the only time in-mast furling systems would be intolerably noisy is when the mainsail was unbent. It’s then that the extruded aluminum luff rod has room to move about in the empty interior space, impacting the sides of the mast. What racket it makes!
Fortunately one could probably fix this either by increasing the luff rod tension, or by looping some kind of padding around it and hoisting it halfway (after attaching a downhaul).
With the sail bent, however, the mast is generally no more noisy (or less neighborly) than any other boat.
Regards,
Scott
Hi Scott,
Thanks for the fill. Makes sense.
I doubt whether luff rod tension alone would stop the noise if the sail was unbent without it being triangulated somehow, hard to do inside the mast. Tensioning halyards rarely works in my experience: just changes the harmonics/period/ etc., but not the overall noise.
My best, Dick
Hi Dick,
Good point! The luff rod would still be like a huge guitar string in the mast, maybe just clacking faster. And, the excessive tension probably wouldn’t be good for the furler’s bearings and other wear parts.
Best,
Scott
We had the mainsail down for a while last fall while on a mooring. An icicle hitch around the foil brought back to the outhaul block on the boom restrained the foil and kept it from banging around. Agree that luff rod tension alone wouldn’t do it. And yes, with the sail bent on, nothing bangs around at anchor inside the mast.
Anyway, I agree with Dick that banging halyards and other noises at night are annoying. Sailors who keep a slab rig quiet will be able to keep an in-mast rig quiet, I think; it’s those who can’t be troubled who will have noise regardless of setup.
Hi Raj
Good information, makes sense. And agree, noise reflects the willingness of the skipper to have a quiet boat and be a good neighbor.
My best, Dick
Hi Mal,
Yes, I have watched that video, but my take away is very different. Note he is doing the furling at anchor head to wind and the terrible kluge of leading a halyard over a hatch. And why did he not demo it while sailing at the start of the video?
Also note that he specifically says that reefing down wind is not doable and that’s a drawback, particularly if you want to do any offshore trade winds sailing. I also think Tom, is, like me, pretty much retired from more aggressive sailing, which is worth taking into account.
I would also guess that your have had the classic experience I have written about so many times of being turned off slab reefing by a bad implementation, particularly since you had a boom bag which is, in my view, a detriment, not an advantage. Ditto single line. I also suspect your lazy jacks were, as most are, poorly implemented and therefore you had to run them forward for each hoist, which is not required with a good system: https://www.morganscloud.com/2013/09/03/lazyjacksmainsail-handling-made-easy/
Anyway, I agree that the Amel is a good implementation of automation, or at least the older ones are. However, be aware that the gear is all proprietary and the man behind it, Henri Amel is long gone, with his old company doing very different boats, so be sure you will be able to gets parts and support for what is a complex system, before you buy an Amel.
Hi Mal,
Congratulations on your new boat. I believe that Santorins are hard to come by.
We’re at the crucial point of having to decide which system to employ on our next new-built boat. In-Boom is out but it’s a difficult decision between in-mast and slab.
We currently have in-mast on our Swan 54, a second hand boat we purchased. She had a mainsail with too much roach and we had many (many!) issues with the mainsail getting stuck up the mast (even after we changed the sail). Hair-raising, were it not that it happened at 8kn of TWS each time, thankfully. So for us, the idea of in-mast was quite quickly shelved.
Yet… The yard suggests we should have in-mast. Saying it is truly the solution for blue-water sailing (our ambition). And they ask us to reconsider.
The one thing I still ‘fear’ of slab reefing is: can I (or my wife) furl the sail alone at 3am? We’re two on board with our kids. Sleep is key. And so waking someone up who has just gone off watch to put a furl in is going to create the risk of hesitating to reef.
Having very little experience of good slab-reefing (I’ve only ever used SunSail’s setup): Can we truly do it alone?
Hi Basile,
Boat yard people are trying to sell you something and in most cases have not been to sea much and so fall into whatever the popular trend is. Ignore them.
I totally agree with you that waking the off watch to reef is unacceptable but based on over 100,000 miles (lost count) at sea on the McCurdy and Rhodes 56 (25 tons fully loaded) we never needed more than one person to slab reef. And I sailed the boat many times single handed without issues.
It is true that generally Phyllis woke me to reef, but that was because I enjoyed it more than she did, and could have the job done in less than 15 minutes, bunk to bunk, including dressing and undressing. That worked for us, but it was a personal choice, and nothing to do with reefing difficulty.
Just fit a good slab reefing system, full length battens, (not required, but makes things even easier) and a good lazy jack system. And if you want to make it even easier still buy an Ewincher. All that added together will be a fraction of the cost of in mast and you will have a more stable, close winded, safer, and faster boat.
And you won’t lay awake nights wondering what the hell you are going to do when the in-mast system jams—three of the friends I have with offshore miles on an in-mast system have been up the mast at sea at least once to clear a jam, very scary stuff.
The bottom line is that anyone who tells you slab reefing is hard to do has never used a well designed and installed system.
You will find detailed instructions for all of the above in this Online Book and if, after reading it, you have questions, ask in the comments: https://www.morganscloud.com/category/rigging-sails/book-sail-handling-rigging/
Ewincher here: https://www.morganscloud.com/category/rigging-sails/ewincher-review/
What sort of boat is she?
Hey John,
Thanks for the clarity of your response!
We’re looking at a Kraken 58. The thing is the owner of the shipyard has done 250,000 miles off shore and swears by in-mast. I think it just goes to show how people can tackle problems from different angles.
But having lived the ‘jammed mainsail up the mast’ story, I agree that there would always be this little niggle in my mind as I go to bed wondering when (not if) it will happen.
I particularly appreciated your article on ‘why going to the mast is good’. The way you brought it also truly helped me to talk to my wife how we view going on deck.
Your website is a fantastic resource. Thank you!
Hi Basile,
Ah, now I get it. I know people love the Krakens and they are very seductive, and the yard are great at marketing, but the reason they are pushing you toward in-mast is that the 58 is way too big for two people to sail safely, with or without automation. In fact the boat is the antithesis of my thinking on a safe offshore boat for two people.
Keep in mind that while only 3′ longer she is half as much again bigger and more powerful than our McCurdy and Rhodes 56.
In fact the Kraken 58 is approaching the size and power of the CNB 66 that killed two people last year: https://www.morganscloud.com/2022/08/22/lessons-from-a-tragedy-at-sea/
And when you put in-mast roller furling in the boat, like in the case of those fatalities, you will be condemning yourself to rounding up to reef, which is intrinsically dangerous, not to speak of scary.
I strongly advise, nay, implore you, to, if you must buy a Kraken, at least downsize to a 50…and go slab.
Also, when you decide who’s opinion to listen to, think about who is trying to sell you a multi million dollar boat, the bigger the better, and who has nothing to gain or lose no matter what boat you buy.
Hi Basile,
Agree completely with regards to John’s comments about the benefits of slab reefing and the down sides of in-mast reefing.
I would add that for any offshore boat, especially a new build, that slippery track (Antal, Harken, others) is a huge benefit to mainsail handling and to safety as slippery track makes it possible, even easy, to reef and douse the main while going downwind: even up to and including gale conditions. This has been a big safety bonus for me: it used to scare me a good deal to round up to face big waves/seas and working at the mast/boom when wind speed could be doubled or worse.
For slab reefing to really be a no-brainer, friction must be reduced. Even top end builders often use good, but not the best most slippery turning blocks, etc when designing their slab reefing systems. Reducing friction makes a very big difference and is usually not too hard to execute: again, especially on a new build.
My best, Dick Stevenson, s/v Alchemy
Ps. There is something quite gratifying (when using slab reefing), on those rare occasions when a third reef and upwind sailing is called for to have a perfectly shaped sail giving good drive and balance to the boat.
Dear Dick,
Thank you for sharing your experience. Indeed, my intention was to find the slipperiest setup to be handled at the mast thus, hopefully, achieving what you suggest.
Kind regards, Basile, S/Y Penthesilea
PS: Couldn’t agree more though I must say that with my current in-mast system I can’t experience it 🙂
Dear John,
Thanks for sharing your insight on the Kraken 58. What is it you precisely mean by more powerful and how does that pose a problem for a crew? More powerful is an often used word but I don’t quite understand how to weigh it. Imagine she’s a slab reef setup, setup at the mast and that we have reliable gear with which to raise and douse the main.
I imagine that with that setup there would be no need to round up to reef.
(Incidentally – having discussed this particular situation with the yard, they say that since the in-mast does not have battens, there is no need to round up but that’s a separate discussion.)
Kind regards,
Basile
Hi Basile,
Great question. That’s the big issue here, boats don’t scale linearly by length. Anyway, the answer is long, but as it happens this thread inspired me so I already have the first draft done on a chapter explaining relative boat size and the factors that determine when a boat is too big for short handed sailing. Look for it in the next few weeks.
As to rounding up to reef, as usual with sales people they have oversimplified to sell a boat. Yes, it is true that if on the right jibe and it’s not blowing too hard it is possible to reef without unloading the sail, but it’s hard on the mandrel and motor and if done in the wrong circumstances and/or on the wrong jibe, can, and probably eventually will, lead to a jam or breaking something. More here: https://www.morganscloud.com/2022/10/17/in-mast-in-boom-or-slab-reefing-performance-cost-and-safety/
Also, I have to say that as a result of these glib and over simplified answers you are getting from Kraken, I’m fast losing respect for them. Anyone selling a boat that big and powerful has a responsibility to be totally frank about issues and not gloss over potential dangers.
Excellent! I look forward to reading it!
We are looking at a Kraken 50 and are faced with the same issue. Dick Beaumont, the owner of Kraken, is exceptionally experienced and persuasive when he recommends in-mast furling, but slab reefing is what we know and what has worked for us. Here are his views
https://krakenyachts.com/which-mainsail-furling-system-is-right-for-you/#:~:text=Slab%20(AKA%20'jiffy'%20reefing,which%20are%20fewer%20but%20longer.
Hi Charles and all,
I wonder what motivates manufacturers/dealers/etc. to come down so strongly for in-mast furling. I remember 20+ years ago I spent some time with the Halberg Rassey boats and dealers and they just were not selling/ordering any boats without a roller furling main. I was very surprised, even a bit appalled.
I wonder what percentage of the higher end boats come with (or are ordered with) roller furling in mast or boom. For example, the Outbound series of boats: a quick glance at their web site seems to indicate mostly roller furling mains often without battens. Do they sell any with slab reefing?
I wonder what percentage of these hi-level dedicated cruising boats get ordered with slab reefing.
Has reefing, in general, gotten such a bad reputation that few are choosing it?
My best, Dick Stevenson, s/v Alchemy
Hi Dick,
There is a simple answer to that: money. The more stuff the dealer can load on the boat, the more money they make. Just like cars: there is more profit margin on the cars with the most options.
Hi Charles,
Dick Beaumont is in the business of selling boats and is a very savvy marketing guy. And he knows that these days many buyers are less experienced, particularly offshore, so more automation looks better and easier to them by definition. It takes real experience to understand that in most cases at sea the simplest system is the safest and best.
That article is so full of errors I don’t know where to start, but let’s highlight just one. He claims that slab systems require turning head to wind to reef, and in mast does not. In reality slab is the only system that can be reliably reefed down wind in all conditions. In mast can sometimes be reefed down wind, but if the boat is on the wrong jibe and so the sail must take a tight turn around the slot edge and onto the mandrel colossal loads are put on the reefing system particularly if it’s blowing, the very time we might need to reef reliably and in a hurry.
Bottom line, if trying to decide on a good safe car, would you trust what the sailsman says over a study by consumer reports who have nothing to gain or lose when you buy a boat? I would say that there is a parallel here.
Hi Charles,
Beaumont writes that it takes two people to reef with slab. That’s wrong too. I have lost count of the number of times I have reefed our McCurdy and Rhodes 56 by myself, ditto our J/109. And there are 36 Open 60s out there as I write with one person aboard and slab reefing.
I am planning on buying a 50-year-old Hallberg Rassy Rasmus 35 from an old man I have been out sailing with for the last two years. He is an electrician, built a tractor (!) when he was a teenager, so the electricity and engine are in good shape.
There is one major concern for me: the boat has an in-mast furling system. I am planning to sail from Sweden to the Mediterranean via the Bay of Biscay.
Twice, when we have been out, it has jammed. Of the three systems one can have: in-mast furling, in-boom furling and slab reefing, the in-mast furling is the most risky for longer legs. With in-boom furling, you at least have the option to take down the mainsail if there are issues.
If I am healthy and still in good spirits, I want to cross the Atlantic (now in my own boat) to the Caribbean.
If I want to change to slab reefing, I have to buy a new mast, and it can end up costing closer to 20 K€.
Should I consider the in-mast furling as a no-go for this boat?
Hi Mårten,
That’s a hard question to answer definitively. So let me change it a bit to “what would you do?”. The answer to that is I would not set off across the Atlantic with inmast roller furling. Not only is jamming a risk I don’t wish to be faced with, the other problem is that inmast sails can’t be reliable reefed in all conditions without rounding up, and that’s simply unacceptable to me. And finally, I hate the performance hit of inmast roller furling sails.
So I would be pricing in the mast change as I evaluated the boat and it’s desirability as against other boats that are available, and position my offer accordingly.
All that said, there’s no question that many tran-Atlantic passages have been made with inmast roller furling and I have friends who are fine offshore sailors with inmast boats.
Bottom line, this is, in the final analysis, a risk reward decision only you can make.
Hi Mårten,
I agree with John on this. I strongly distrust any type of furling. Even furling headsails are on my list of not trustworthy devices, even though in mast and in boom are far worse. Still, with knowledge and careful use you can make it work, of course.
I think scale is an important factor here. The Rasmus is in this context a relatively “small” boat, meaning many of the relevant loads are possible to handle manually. Parts are reasonably light weight. On say a modern 50-footer, furling is more tempting, due to the large heavy sails, but problems are also much bigger and typically nothing can be handled manually.
I think you can do proper maintenance of the in mast furling system, (do it yourself), get to know every detail of it, experiment with what causes problems and what is safe, have all spare parts available, and then sail your boat safely anywhere. I’d treat in mast furling as a known weakness of the boat, one you can control, not a disability, a no go problem.
There is no boat that doesn’t have any weak points, imperfections. We should know what they are and how to treat that side of our boat. The in mast furling is just one of those. I would certainly prefer to change to slab reefing, but I think it doesn’t make sense to buy a whole new rig in this case.
Hi Stein,
I agree with your analysis although I differ with you since I would price in changing the rig, but, as I said before, that’s a personal call, not a right or wrong one.
One other thought: whether or not the mast is original and depending on how many miles and years the standing rigging has should be taken into account in making this decision. For example, if the rig is 50 years old and the standing rigging coming up on 10 years there is a better argument for replacement. Bringing a 50 year old mast up to ocean safe spec could be very expensive.
Hi John,
I agree with you on all of this. If it was me wanting to spend a lot of time offshore with this boat, I’d definitely get a new rig. I would probably do most of it myself, to know it’s done right and keep costs down.
Still, I like to appreciate that for most cruisers, that’s not possible. They don’t have the tools and skills to build a rig, and getting one built might cost as much as a nice but old boat is worth, even after the change. This means that quite often, the options are:
1. Do what you can to improve what you have, without going for major investments, or
2. Drop the dream of long distance cruising.
Somewhere in between «anything that floats can cross oceans» and «the boat must be seaworthy in all respects for any situation», there are several levels of viable compromises. Not ideal solutions, but the trip starts. If choices are good, like what weather we will risk, the downsides are usually acceptable.
In this case, your logic is 100% right, but it means he should not buy this boat, unless it’s given to him for free, and probably won’t go sailing far anytime soon. I think there’s a softer middle ground. I do agree that a new rig should be planned, but not necessarily immediately. First get moving. Perhaps he will want to change to another boat. If so, the new rig is money and effort down the drain. The cost of new rig and sails done professionally is most likely significantly more than its possible to sell the boat for.
That’s another way to say old boats aren’t worth fixing up for long distance cruising, which is both true and false at the same time… «It depends», as has been said on this site many a time.
Hi Mårten, John & Stein,
Interesting discussion -> at the risk of further topic drift…the Rasmus 35 looks a candidate for being a “modern” classic yacht and if cared for should hold or even increase in value as other examples less cared for are lost to the market!
Like a classic car, a classic yacht brings pleasure in the sailing AND stewardship. And unlike a classic car or wooden / steel yacht, the newer models of this Rassy can’t rot or rust (after hull No.3 with the first two being mahogany according to HR database).
With sensible decisions the classic element could be sympathetically retained. It may also qualify for classic yacht sailing events which could be fun in itself but the original elements need to be “reasonably” retained I believe..?
From a quick glance at the photos: https://www.hallberg-rassy.com/yachts/previous-models/hallberg-rassy-rasmus-35 the rig appears to have in-mast reefing from the absence of slab reefing lines. But the manual and brochures in the Rasmus 35 database are not clear on this.
Confusingly the sail plan shows four horizontal battens and a moderate roach, which suggests slab reefing.
I really don’t believe HR would have put out a rig on a boat they consider “ocean ready”, which jammed up. As Stein suggests it could be lack of maintenance or perhaps more likely a replacement sail, wrongly designed or poorly constructed for the mast – or both?
Anyway, another consideration…?
A few years ago, I had a client with a 6.8m long in-boom reefing system from Furlerboom, a Danish company. Not only did the boom angle have to be 100% accurate, there were constant problems with the luff getting jammed in the furling drum. It then happened twice to the client that, with more wind, the inner carbon tube with the rolled-up sail bent so much that it jumped out of the aft bearing. At that point, you have no control over the sail whatsoever.
The company Furlerboom.dk claimed it was an operating error and there was nothing they could do. I then sawed the €24,000 boom into small pieces and scrapped it. After that, I installed a normal boom with a conventional triple slab reefing system. The client never had any more problems with reefing.
Hi Dieter,
Your story highlights a common problem: it’s all too easy for companies building these systems to blame the user rather than fix the product. My thinking is that if a dopy person at 3 am in a rising gale can’t use it consistently without failure it does not belong on an offshore boat. So far the only system I have seen that passes that test is properly installed slab.
Hi Dieter,
Since this is a comment on an article comparing reefing systems, may I clarify a few things for readers coming later.
For background, we have had a LeisureFurl boom on our 14.5 m sloop for more than ten years and been offshore with it. We sail everywhere, because it is so easy to use and the mainsail so efficient with 6 full length battens.
I agree completely with John that in-boom reefing is not idiot proof as the makers tend to advertise. It takes an investment in time and understanding to set-up well and operate reliably.
But then in-mast is the same from my experience of an HR ocean passage. And slab reefing too needs an investment in great equipment and takes time to set up correctly, especially if the controls are lead aft to the cockpit.
The boom angle on our boat (and as I understand it, any in-boom system) doesn’t have to be 100% right. It just has to be at 90 degrees to the mast or more. It can be 10 or even more degrees above perpendicular… no matter. If the boom is even slightly below perpendicular, the sail will roll forward and jam up. If the boom is above the perpendicular the sail will roll slightly aft.
There are two simple tips to prevent jamming at the tack.
Firstly, have a powerful solid boom vang set so then the vang is released, the boom automatically lifts into its reefing position every time. 5 to 10 degrees above perpendicular is ideal.
And second, to tie the clew and tack positions slightly aft along the boom, so not too close to the gooseneck (this took us over a year to discover). This tip is particularly important for being able to reef downwind with in-boom.
I also wonder about the mandrel bending so much – a carbon fibre tube would be twice as stiff as our aluminium one. With our set-up the mandrel is attached to the aft and forward ends with grub screws. These are NOW set-in with Locktite, and the mandrel physically can’t pop out. It would amaze me if the Danish engineered system wan’t similarly attached.
But I COULD believe that the original rigger that set-up your client’s boom didn’t use Locktite to attach the mandrel (stupidly common) and the bolts / screws had worked themselves out. In which case the mandrel will have bent as designed and there would be nothing to stop it popping out when bending.
So my tip three for trouble free operation is to remove all the securing bolts / screws – not just on the mandrel but also the goose necks, and reset with Loctite.
Hi Rob,
Great to get first hand competent knowledge. I still will not have a furling main, but this made me a bit less critical.
However, I still wonder why it’s rolled inside the boom, not just around it, like in the old days. Then everything is easy to see and access, the mechanics are far simpler and stronger, plus it’s cheaper and lighter.
Still I don’t want it, but that’s also true for most of the «comfort» boat equipment around.
Hi Stein,
Good point about the old roller mechanism being simpler. For us the main benefit of boom based roller reefing is we have a full battened mainsail with a BIG roach, controlled by a solid and very powerful vang. We have awesome control of the mainsail both in shape and size all from the cockpit with just a few lines. This enables us to run a 103% furling jib instead of the class normal 140% genoa without any material loss in performance.
With the early boom reefing systems where the mandrel and boom were the same thing, any vang arrangement would be horrible at best and dangerous at worst. I believe most ran without a vang and just a topping lift controlling boom angle for reefing. But they probably didn’t have mainsails with full battens and big roaches.
The sheeting would also have to be from boom end and I guessing this would have the main sheet and traveller in the cockpit with all the dangers this presents when cruising. Our traveller and sheeting is forward of the dodger so this wouldn’t work for us.
Our slight first mate can and does control all the sails from the safety of the cockpit. If something happens to me (not getting any younger) then she can sail home, or lower the sails and motor to safety – she’s a natural navigator..! But there is just NO WAY our first mate would leave the relative safety of the cockpit to reef at the mast in 20 knots, let alone 40 knots…not going to happen.
We bought and installed our in-boom system and mainsail to enable the above attributes for offshore, just before I joined AAC. If I had my time again, knowing what I do now from John’s articles, I would have carefully considered a new mast track, proper cars not slides, a new boom designed to allow an outhaul and three reefs, a functional lazy jack system and new mainsail with three full reefs.
But FOR US, all this would have to be run from the cockpit, and all those lines would need to be accommodated somehow and somewhere..!
Hi Rob and Stein,
I’m old enough to have actually used the old outside boom roller reefing (you could not practically furl with them) and they were truly horrible. Too many problems to go into here, but one of the worst was no vang, as Rob points out. I was also sailmaking at the time and helped several boats so equipped to change to a slab system with universal approbation in all cases.
Hi John,
I’ve also sailed several boats with the old outside roller booms, of which all but one had rebuilt it to slab reefing. I guess that says enough. The one still using it mostly sailed inshore and it was a small boat. It did actually work ok, but slab reef is easier and quicker.
Most multihulls have no vang, since the boom is usually close to the deck. Some of them have very long mainsail tracks, which in some ways do a better job than a vang, but most don’t and still do fine. Good methods make things work.
Roller furling, any form, is to me a solution to a non existing problem, giving issues that should be deemed non acceptable I’m not expecting to get many followers on that opinion. 🙂