niko

If you want to go really expensive: Torqeedos (expensive) solar charging system (http://www.torqeedo.com/us/hn/products/cigs-solar-charger-62-w.html) for their (really expensive) high efficiency e-motors. If you don't care the money it gives you a system which runs an electric motor directly by the solar panel, recharging the battery when the motor is not used with a total weight (motor, battery & solar panel) of 18kg (~36lbs). They say it's so efficient that the solar panel recharges the battery faster than the electric recharger. It only falls down if you have neither wind nor sun for two days in a row. If it only was half the price...

I think you're right. It's just in the long direction. I have no idea what's needed to enforce a mast. C/F in the long direction is certainly important. I can't tell how important the other direction is. In Germany.

No problem. I'll drop you an email.

Complete birds mouth carbon composite would also be an option. Although I think having the exposed bottom section (top will be in luff sleeve) with the mast step, the deck, the downhaul and the snotter attachment as alu tube would less prone to damage. Ideally I'd try to get 10' of alu tube for the bottom section and extend it by a tapered birds mouth composite to 18'. Do you think a flexible carbon fibre hose like this one would work to reinforce a tapered birdsmouth: http://shop.r-g.de/en/Reinforcement-fabrics/Carbon-fibre-hoses/Carbon-flexible-hose.html Seem like much easier than winding a tape around the birdsmouth.

The CS15 masts are specified as 2 1/2'' (63,5cm) with wall thickness of 0.0625 (1,58mm) for the bottom section. So the other tubes are 4.5mm more diameter, but 30% thinner walls. Guess I really need an expert. Top section is planned to be birdsmouth & carbon.

It seems I can get my hands onto 68mm (2.67'' or 2 2/3'') 1mm (0,04'') 7075 aluminium tubes. It seems to be about twice as strong as 6061 (I found 280 Min.N/mm vs. 540 Min.N/mm). If these tubes would do for the bottom 10' of the masts it would save nearly 1kg or 1/3 weight each. Would this work?

I started to study the CS15 plans and couldn't figure out the sailplan measurements. For example the main mast has a measured length of

Then you'll loose the benefits of the unstayed rig

I wanna store the sails wrapped around the mast and then lay the mast when storing the boat on the dock. They have this nice floating dock/peer here. All you have to do is pull up the boat about 1' onto the dock. I just fear they don't dig the mast hanging over the boat 3' and the cover would go over the complete boat much better if the masts don't look out. I'd have the third mast step anyway. Not much work, more flexibility.

Perhaps I should have specified better how I would place the zipper. The zipper goes horizontally from the leech to the luff. Luff pocket sails have broad gaps in the pocket where the snotter attaches. I though about having a slit in the pocket - perhaps even overlapping - perhaps even with with velcro - where zipper meets the luff. I can't imagine the zipper having more influence on sail shape than the sprit boom - which again doesn't seem to be as bad as most people anticipate. All this is not about easy reefing on the water. It's more about a simple setup with good airfoil and less lines.

Hi everybody! I just received my plans for CS15 #19. I plan building her spring 2010. Or rather having her built. I personally don't have the time to do more than some planing and supporting work and therefor have to find a pro builder for the most of the work. Too bad, but still I'm so much looking forward seeing her grow and finally - hopefully - float. Now to my idea and the question what do you think about it. (I'm afraid you gonna see more of that :-) I plan to have the luff pocket version of the sails. I like the simplicity. Eliminating tracks and halyards is quite intriguing and I like the clean air foil I still know of my laser sailing days. The one big BUT that remains is reefing. As other have written, roller reefing around the mast pretty much destroys the windward ability of the rig. I'm definitely gonna have the third mast step (nice to have as an option). But going sailing on a windy day I can imagine not wanting to miss the virtues of the cat ketch. I think one could add a mast extension of about 3' or 3' 3'' to the bottom of the masts to achieve the final height. Now reefing would be done by removing the extension and zipping off the bottom part of the sail with a zipper. Pros: * The sail still would be a really clean air foil when reefed * The masts would be shorter which would bring the weight down. * Without the extension the masts would not be longer than the boat any more. Cons: * Can't reef on the water. We're on a lake here anyway. With some planing and caring for the weather forecast that's not a problem for us. Reefing with other systems (like restepping the mizzen) are best done in sheltered waters, too. * More weight. But even when using twice the wall thickness it would add no more than about 2 (or at most 3) pounds to the overall weight of the mast. And these 2 pounds are located at the very bottom where they hurt the least. * Must be strong enough. Laser masts are dividable so it should be possible to make the connection strong enough. It's not a problem to get the right aluminium tubes with outer & inner diameters so that the extension could be made by gluing a 8'' or 10'' tube with 2.5'' inner diameter and 0.13'' wall thickness onto the bottom part. See attachement. What do you think? Especially Graham?

There are special centerboard gaskets: http://www.apsltd.com/c-3020-slotstrip-centerboardgasketmaterial.aspx

Very useful. Thanks!

I'm looking for a family-friendly, save day and weekend sailer and the CS15 caught my interest. I have some question concerning the CS15 and would be grateful for some advice. The boat is gonna be stored on a floating pier (is that the right word?) about 1' above water level. On the edge of the pier is roller to ease pulling the boats onto the pier. I want to be able to slip the boat single-handed. This rises two questions: 1. How much is the weight of a fully rigged and ready-to-sail CS15? 2. Does the centerboard extend below the keel-line of the CS15? Will I be able (besides the weight) to pull a CS15 over a single horizontal roller onto the pier? 3. How long are the masts? Would Laser-Masts (they're 5.37m/17.6') work? 4. What about the roller furler masts of the hobie bravo? (5.8m/19') Not stiff enough? Making furling & sail storage as easy a possible would be really nice. 4a. Thoughts about roller reffing in general? I read bad thing about roller reefing masts in the carbon mast thread (http://www.messing-about.com/forums/index.php?topic=6760.0). But CS17 Kirsty Ann (http://www.batchelors.net/personal/boat/cs17/rye.htm) seems to have a roller reefing mast the kink I was thinking of. 5. Has anybody tried a mast step with a partner? Would it be feasible to ease mast righting? Thanks in advance for the help, regards, Niko.