Cat sail thoughts?

[Westcoast DAD]

I'm researching the Sun Cat and the HC. Watching many videos and having a sailboat racing past I'm curious if anyone one has moved to having multiple full length battens it seems to me viewing the light air videos that two or even three full length battens would help hold better sail shape - pair that with a basic boom kicker to keep the boom weight from closing off ie curling the trailing edge of the sail would make a sizable difference in light air sailing.

Has anyone tried this? The intention would not be to improve point but to improve the sail shape and provide better lift / air flow in the light air. From what I can tell the partial battens and boom weight in light air causes the trailing edge to curl and fall to windward which is not great for maintaining flow over the sail in light air.

Thoughts?

[Westcoast DAD]

I do realize that the Gaff being hoisted tight can instigate that trailing edge being pulled too tight also sort of the same effect of cranking the boomvang too tight on a standard cutter rig.

[Craig]

I too thought about the efficacy of a(loose footed) full-batten rig. The only negative I could come up with was that in very light air the battens might not allow the sail to assume an optimal shape. Whether that would make a significant difference in performance is up for grabs. If I were to replace the sail on Kailani, I would opt for a loose-footed design for sure.

[Westcoast DAD]

Loose footed and maybe at least two full battens. I just realized another advantage to moving to additional full length battens would be that they would help keep the sail organized over the boom when you drop it.

[Westcoast DAD]

I think any options that help reduce the baggy pouch look vs improve the airfoil shape would make big improvements in the light air performance possibly enough to where people would sail longer before opting for the iron Genny. The cat boom is very large by nature of the CAT rig - so having the ability to reduce the hung weight of the boom on the sail which dramatically impacts sail shape would be a good modification for the light air sailing. Going loose footed meaning not bolt rope through the boom makes the outhaul adjusting in light air far easier and more accurate no bolt rope friction holding things up on the out haul adjustments. Also a nice trick one solo sailor I know put a quick release on his loose footed main so as he pulled into the marina he could blow the tack off the sail and let it flap loose if he was out of options to depower the sail by him self.

Also no bolt rope in the boom slot means you could have a sail bag built to slip into the bolt rope slot on the boom - add a long batten down each side top edge of the sail bag and incorporate it into a lazy jack and you have an instant bag for your sail to drop into - run a zipper up the middle on the top and you've bagged your sail in a matter or minutes.

[Westcoast DAD]

Ok so here is an example of the boom bag idea
http://www.youtube.com/watch?v=kax8fVwFniU

I don't like how high cut this design is I've used much less bulky lower cut bags before but it gives you the general idea. You could have a canvas shop make a bag with a bolt rope running down the bottom center line for the boom then have battens sewn in to that you connect to a lazy jack to help hold the sides of the bag up then a simple zipper up the middle on the top section. The one I used in Croatia had very little structure to it and worked great on the Sun Cat and HC this would make for packing up the main a very fast process and it could stay fully protected while trailered or stored etc.

The one that Compac had done recently on a HC had lots of odd ball stainless structure work done to hold the bag up which was mounted too the boom thus adding weight to the boom and cost both of which you want to avoid.

[Craig]

Kailani was ordered from the factory with a Mack Pack and a Boomkicker. Love both. Would not leave home without 'em! The Mack Pack unlike the stack pack is NOT attached to the sail. Furthermore it is open at the bottom and is not attached to the boom, having straps which run under the sail between the bolt rope and the boom to stabilize the sail bag. Works like a charm. The forward part of the sail bag is attached to the mast with hooks and twist-lock fasteners which can be released when dropping the boom below the hinge for trailing. Lazy jacks are integrated by the way. Bag is zipped up with a continuous line zipper so the bag can be zipped/unzipped from cockpit.Can post pics(maybe!)if interested. Nice system! 

[Westcoast DAD]

Craig - com-pac sent me pictures of your boom set up. Not a fan of the stainless frame work attached too the boom. All the boom bag setups I've used were nothing but a long bag attached via bolt rope to the boom with long battens in pockets on each side with lazy jacks holding the sides of the bag up. Fairly light weight and simple.

No doubt a boom kicker I think would greatly improved light air sail shape given the cat boom is pretty big and heavy to start with - remove the boom weight hanging on the sail and your light air sail shape is dramatically improved.

[capt_nemo]

There is definite potential value in a boom kicker and full battens in improving mainsail shape in light air.

Nevertheless, I opted to improve my Sun Cat's light air performance by first adding headsails and then making a Nylon Mainsail (set flying on a gaff).

The first headsail was a home made Orange Nylon Drifter of 38 sq. ft. which was set "flying" in the small fore triangle area forward. Not only did that little sail dramatically improve performance in light air but it created a slot effect improving the airflow across the main and overall efficiency of the rig.



Then I made a Nylon Mainsail which I set flying along with the small Nylon Drifter.



Still not satisfied I made a 4' Bowsprit and a masthead 75 sq. ft. Drifter to use with the stock mainsail. It is easier to handle in the larger fore triangle  area and has exceeded my light air performance improvement expectations.



A home made working jib has provided the "drive" I found lacking under certain conditions.



Just some food for thought.

[Tom Ray]

One of the guys on TSBB's catboat forum had a loose-footed full-batten sail on his Sun Cat. Might have been Dick Herman?

As I recall, he went back to a more standard sail when he wore that one out. An interesting aside: when he did, the sailmaker initially messed up his sail, putting the clew reef in the wrong place. My friend Joe bought the messed-up sail from her. It is on the Sun Cat currently for sale at Punta Gorda Yacht Brokers. I sailed with it once and it was nice. I think Tom Scott has a video of that sail on youtube.

I don't think changing the shape of the sail will help all that much.

The original Sun Cat design had a Marconi rig with 160 sq ft of sail area and it had no keel, just two bilgeboards. Our Com-Pac boats have 150 sq ft of sail and a ballasted, fat keel. The light air performance of a Sun Cat is never going to be all that good with 150 sq ft of sail, no matter how nice you get the shape. It's a power to weight/drag problem.

The solution, as Don says, is more sail area. The one that has worked best in practice is Scott Widmier's 180 sq ft sail. He convincingly won the Sun Cat Nationals in a breeze and in a near calm. Scott is a very good sailor and is even more accustomed to light and fluky winds than the Charlotte Harbor crowd, so part of it was his skill, but the extra square feet seemed to me the larger difference. Don gets some of those square feet with his jib, which gives you a slot effect but also has its own drag penalty.

If you really want a Turbo Sun Cat, buy one of the old ones built by the Sun Cat Company in the 70s and 80s. Cut off anything that doesn't make it go faster and put on a Horizon Cat rig. Still class-legal, since the Sun Cat Class Rule only says you must sail a hull that is arguably a Sun Cat hull.

[Craig]

I never gave any thought to the stainless frame on the boom and hardly notice it now. It does allow the aft end of the sailbag to be a little roomier. By the way, the Mack Pack can be "undeployed" easily and rolled up along the boom for racing or long passages. The ties to keep the bag rolled up are built-in. Rolling it up cleans up the airflow along the foot of the sail. The Mack Pack can also be removed completely without removing the sail should repairs be needed. Likewise if the sail needs work or to be replaced, the sailbag does not have to be sent out also. Handy especially if one wants to use a sail loft other than Doyle. Another feature I like is that because the sailbag is not sewed to the sail at the foot, water can drain out and air can circulate. I suspect Mack has a solution for loose-footed sail installation. I researched both the Doyle Stack Pack and the Mack Sails Mack Pack and felt the Mack Pack worked better in my circumstances. Both companies are semi local so that was not an issue. I can attest to the excellent service by Mack Sails. Kailani was the prototype installation on  the Horizon Cat and needed to have the fit adjusted. Mack was on site within a couple of days and made the adjustments right at the boat. Aesthetically, the Stack Pack is a little cleaner looking, the Mack Pack a little more utilitarian for the reasons cited above. Both work very well indeed! 

[Westcoast DAD]

I hear ya Craig if it works and your happy with it thats all that matters. I learned a long time ago that when it came to canvas and sail stuff local lofts and the in the know active sail builders who tend to move around to the lofts with the best working situation be it pay and management or otherwise are who you really need to keep tabs on LOL

The canvas stuff be it dodgers or otherwise the local guy with a good reputation is always going to be better than someone across the country given you always need little adjustments or fixes done. Any good marine canvas shop can build one of these with some pre planning and design thoughts put into it.

No doubt adding sail area will improve light air performance however just improving the existing sail cut when there is lots of room for improvement will help too without getting overly creative in adding bow sprits and such. Not to mention there are always other advantages to improving sail shape which results in easier to read and trimmed sail, possibly easier to reef or reefed sail that holds a nice shape, a sail that is easier to handle when you drop it or raise it etc lots of advantages to be had for sure.

I connected with Dick recently we have a loose plan to meet up in the spring so I can check out his boat he lives about an hour and a half from me. He said that he has a Hyde sail and Rudder Craft rudder and is really happy with them so far. No idea if he went with the loose footed or not. I changed my Ericson 28 to loose footed and my U20 was standard loose footed I would never go back to the bolt rope in the boom and future boats that would be my first change if they had the bolt rope boom set up.  I would never expect the Cat's to be fast I just like really nice looking easily trimmed sails that handle well. As for racing I'm pretty much done doing that on a serious level but in a fun non serious chase I no doubt would enjoy dusting off the old racing skills regardless of the boat I'm sailing.

I really do think there is a growing need for super low key hey meet everyone at X if your interested and well chase each other to Y and have some fun type gatherings given the regatta stuff has become so dang serious its no fun anymore. Not to mention costly. The low key gatherings also are far more family friendly for young families sail what you got vs you need to have the latest and greatest high speed whatchama call it gadgets and boat etc.

[Craig]

Thats what I love about catboats! Easy, low anxiety sailing. And by the way cats can be surprisingly fast on some points of sail! Also, as you may have gathered, I am a big boomkicker fan too, having had them on both the Suncat (Thanks Tom Ray!) and our Horizon Cat.

[capt_nemo]

Westcoast DAD,

You are so right about the NEED for low key gatherings, especially where there is some time set aside to conveniently check out other boats in person and discuss boats and equipment with others.

The most enjoyable gatherings of kindred spirits in my sailing life have included such an opportunity which was greatly appreciated by those in attendance.

capt_nemo

[Craig]

Nes plus ultra!