I am getting a new mainsail for my I17 it currently has a very small square top, Nacra have said that bigger is better,They have mentioned pentax as a material, which will match my jib. Why just go square why not go up and out ? Like the 18ft skiffs do. Any suggestions please..

I would definately say go with Square top it gives a lot more drive up top, I've only had mine on the 5.7 Taipan for 6 sails and swum 4 times but I was going faster each time. Your mast section is important if its too light you won't be able to rotate much or it will bend over backwards when you pull the main on and sideways if you dont have the main on enough. The design is really limited by your class rules on size and shape. Does your class include the mast in the sail area? If not you can get a stiffer section like an F18 which gives you the stiff mast and technically extra sail area. I know the Stingray sailors pick up about .4m2 doing that.
Put a camera on your boat when you first put the big head on and post it on you tube, I've kept my mates laughing for hours with my videos

Were those capsizes done whilst bearing off around the windward mark by any chance

Don't worry Jeff, I'll have the camera ready.....

If you want a laugh have a look at this from last Saturday we had a big reach, I was crew on my boat with the traveller and didnt let go quick enough ended up slamming into the spin pole and hanging there stunned for a while. Very funny
http://beachcatsaustralia.ning.com/video/taipan-57-pitchpole-22nd-jan

This is behind a registration wall. Can you put it on YouTube or dailymotion, aka some place we could look at it without registration?

Sorry I didn't know you had to register
http://www.youtube.com/watch?v=YbiznaTG2AY

Jeff you need to get your crew working for his ride. Make him trim the main, the rapidly moving back ground suggests you're using the tiller a lot.

G'day Scarecrow they were just off shore puffs officially measured on land at 56km/hr throwing us around, if you watch Fergs on the tiller he's pretty steady. Now I know you guys are there and you guys have heaps more knowlege of boat design, sails and masts. I would say that if Devon's mast has about 50-60mm pre bend he could carry a bigger head main and lessen his prebend to 20-30mm or less. How do you work out how big the head can go, how much prebend? You need the camera on the spin pole to share the pain Chocko

Working out how big a head can go is easy. You keep making it bigger until the mast breaks.

Jeff,

The crew in the video (I presume you) didn't let the main out ONCE in the upwing footage. In a non race scenario, driving up obviously worked out in keeping the boat upright. In a race situation, however, this is slow as molasses. The crew should be working the main in conjunction with the skipper to keep the boat at an optimal angle of heel at all times (windward hull just kissing the water), which generally equates to best VMG upwind.

A skiff rig needs to be a LOT more automatic than a cat.

I think Devon wants to avoid breaking the mast, I found the mast tuning is unbelievably critical, I was keeping up with Fergs with my small head main, even beat him in our distance race when he had the new Goodall Bighead with new mast supposedly tuned for the sail, he lessened his prebend by 30mm and softened the diamond wires a couple of weeks ago and smoked me. I havn't heard of a Nacra dealer doing different sail design, I thought it was all class stuff, did he say he's done it for other I17's. Sorry Sam my bad,I don't want to hijack the thread but to save my already ragged reputation, I'll give one last link to me sailing in a blow when another 5.7 pitchpoled, it shows me and my wife mucking around keeping the boat flat.
http://www.youtube.com/watch?v=SmzwEhc_83w
or
http://beachcatsaustralia.ning.com/video/sailing-10410rain-and-30kt

Im very attatched to my mast as it is only 3 mths old, we just launched another I17 and we put a F18 spinaker on it, had to go a little higher up the mast but it worked ok in light breezes, lot of sail for 1 up and the mast had a lot of bend but it is a wing shape and was rotated, I would like to have a bigger head LOL wouldnt we all but also go up higher as the 18ft skiff do, will talk to nacra about this as they are the ones to give the ok and so far they seem to want to go that way...Thanks for the advice

Devon which mast extrusion do you have? Is it the infusion one? Given you have less righting moment, you could hang just about any main off it that you could make fit.

Devon's boat and Alex's with F18 spinnaker

OK, speaking of squaretop sails - in looking at the Tradewinds pics I noticed that one of the N-20s (red, sail #11) had a main with much more of a square top than the others. Unless I'm not seeing things correctly. What's up there? New Nacra cut stock sails? Calvert? How did the compare? Curious I am...

It was a sail Mark Smith had made from an aftermarket sailmaker. I thought Trey Brown was supposedly spearheading new sails for the class. Last word was they were planning on a new spinn first. I heard he had two new ones at a recent regatta but not sure what the details are. I'm going with another maker soon myself. One guy in the GT last year had a new design main that he had C and C sailmakers do for him and he was pretty fast in the light air. Unfortunately the squall on day one ruined it for the rest of the race.

I believe Kirk at Key Sailing now has the two test kites for new development. Trey and I had them at an event at Nigel's in the late fall but they were rigged for end pole snuffer so that we couldn't try them. We put one up in the parking lot and noticed the luff was significantly shorter. Hard to see a lot else without any wind. Should be a lot easier on the spin poles though by not requiring as much pre-bend.

I believe the new kite is coming out soon but don't know the dates. I've asked Trey to give an update.

Interesting. At what time will this information about these two new design spinns be made available to the class? Are they available for some of us to try or just for a select few? I hope Trey will chime in here sometime, being that he is the Class President and all.