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Comparing a Waters Wingmast Mk.l with the Mk.ll
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QUESTION: I am very interested in your Waters Wingmast, but see there is now a Mk.l and a Mk.ll for a different range of sizes. As I need a mast that is on the border line between the ranges indicated for the two models, can you please elaborate on the differences, pros & cons etc, and whether one can upgrade from a Mkl to say a Mkll without buying another manual. Thanks Mike. Evan-Mc, CA
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ANSWER: Sure, and thanks for your interest in this unique way of getting a very efficient wingmast by home-building. To build it is different work, but no more difficult than other boatbuilding tasks and the result can be extremely rewarding. Both manuals are very detailed and you should find all the help you need contained there …. and there are also now others who have succeeded who may be accessible for further advice and encouragement. Although the construction concept is the same for both designs (a CF shell built around a central web), there are a few differences that may be important to you and certainly worth understanding.
First, the Mk.l has a rounded nose with a diameter of about 80% of the mast width. For moderate sized wingmasts, this gives a section that is less critical re the exact rotation angle due to less risk of stalling. However, as masts get bigger, this nose diameter starts to get quite large, adding to general air resistance. So when it gets close to about 80mm diameter, it was decided to amend the mast section so that the nose would not exceed that nominal value and this results in a more elliptical section where the nose diameter may vary from 50-70% of the mast width. While this looks on paper to be even more elegant and aerodynamic, it does require a little more care to tune its rotation for the best efficiency, requiring that the mast axis point into the apparent wind within a reduced tighter range compared to that of the Mk.l round nose model. IF that is done, then the Mk.ll can theoretically be slightly more efficient. If not, it will stall and then will almost certainly be less efficient.
With the larger sizes of the Mk.ll model also comes some changes to details. Here is a list:
The bolt rope option, while still possible, is replaced by an installed track for the Mk.ll design, so that batten-slides or batt-cars can be used .. something that many sailors prefer for easy raising and lowering when dealing with a large mainsail. Personally, I prefer the finer tail and added efficiency of the bolt rope design, which I find can be made to work up to about a 12m (40ft) mast, though this is probably the practical limit. It should be noted that if your experience with bolt ropes is poor, you need to ask yourself if the mast concerned was rotating or not. Just by adding rotation to your mast will significantly add ease to the way your sail can be raised and lowered, as it takes off a lot of friction at the side of the slot. But I agree, even with a rotating mast there are limits, so a 40ft luff is mine. Over that, definitely plan on using a track. I should say that the option for a track is also included in the Mk.l manual.
Other strength issues also kick in for the larger Mk.ll.
The Mkll features a heavier, integrated mount to take compression at the pivoting ball.
The Mk.ll replaces the fixed beak at the hounds (which is fine up to 33ft (10m) masts), with a pivoting one that reduces stress in this critical part and also allows the mast to be turned 90 degrees to stall the aerodynamics when the wind is too strong..
The Mk.ll also accommodates more internal halyards as are common for larger boats with a wider range of foresails to be flown.
The Mk.ll also uses a mast rotation tiller that is more typically connected to blocks on the deck or cabin top to give maximum versatility for fine tuning , whereas the Mk.1 shows a tiller connected to the boom as a limit to its relative angle with the mast .. a system that works fine for the less critical mast angles of the Mk.l design.
The Mk.ll also shows a streamlined spreader design for less air drag.
The Mk.ll shows a more traditional gooseneck mount that is strongly built on to the mast wall, whereas on the Mk.l, the recommended boom is a rotating one that is connected to a shaft through the mast, not unlike the original Farrier one, except that the crank is removable to avoid a 2nd hole in the mast for the slide-in handle, that can weaken the mast and add construction complexity to the wingmast.
Finally, to handle the extra halyards, the sheave box at the top of the Mk.ll mast is of a different design to contain more sheaves for the extra halyards.
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Having outlined these differences, it’s important to note that there is no technical reason that any of these optional design features cannot be interchanged between the Mk.l and the Mk.ll designs, so if you want to take your pick of features, you can purchase both manuals for just $100 over the current cost of the Mk.ll manual, but still with approval to build one mast. If you wish to be able to build a mast of both designs, you will need to sign a waiver and purchase a Manual for each mast. If you wish to build more than one mast to either of the designs, please contact the designer to work out a Royalty arrangement that will be of far more benefit to you than buying a Manual for each.
It should also be noted that when it comes to reefing with a wingmast like this, much consideration should be given to using a custom designed storm mainsail. It has been found that a tall, slim stormsail with an aspect ratio of about 6:1 works extremely well behind a rotating wingmast, with the mast now becoming about 20% of the total chord of the mast-sail combination .. so approaching closer to a fixed wing. This provides a way of reducing area and heeling, but without giving up the upwind efficiency that a rotating wingmast can offer and on tests, an upwind speed of about 80% of the full sail performance was achieved with only 1/4 of the mainsail area. So, once you have your Waters Wingmast installed, instead of deep reefing a large main, consider changing to a short foot storm main, that is both easy to stow away and more relaxing to use while still sailing fast.
Hope this answers your questions.
[NOTE: .. due to other priorities, the complete Mk.ll Manual will not be available until Spring 2024, though individual details will be available in 2023].
Mike 2022
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