Rather than copy all the posts from the previous "Fat Head Sail" thread into this forum I'll just provide a link to them here. Then the discussion can continue from here.

Fat Head Sail - Page 1

Fat Head Sail - page 2

I have recently purchased a second hand mosquito in Queensland as a trainer for a few years before getting into an F16. Because there are no other mosquitos in Brisbane and the old sail was shot, I decided to purchase a new main with an oversize head.

The taipan sailors at the club have mentioned that it looks good but I suspect this is based on aesthetics rather than performance potential.

Unfortunately I have been rebuilding broken rudders since Christmas and have only been out a few times beforehand (only two races). Since this is my first time in cats, my crew and I are still learning the ropes and there are no other mozzies to sail against performance evaluation of the square top is a long way off. However, I will try to keep this message board updated on VYC handicap results against the taipans and such as this would be a reasonable indicator.

One quick advice regarding squaretops. Don't pull the head in to the centreline. Try to sail with a nice continious amount of twist. The top should nearly always be about 200 to 250 mm out from the centreline. You'll need this twist profile to reduce pressure on the top and to cut down on the tip vortex which can add alot of drag to the rig. Pulling in the sail to tight will feel like the boat is bound up. That it should go alot faster but won't. A squaretop that is too far open (twisted off) will feel underpowered, you'll be sitting in and going slow as well. Finding the right twsit profile can in some cases feel like you just dropped a large chunk of lead. The boat will feel free, agile and quick again. Remember induced drag on the rig accounts for about 30-35 % of the total boat drag and it is the single biggest drag component in relation to hulls drag, board drag. It can make or break your race quickly.

Wouter

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From my foot down measures as a mosquito main, from my foot up does not measure (approximately the top third is over size).

Hi Nickb,

I would be interested to know, what is the actual measurement from head eyelet to first batten position at leech? (Head width?)

It looks like it is bigger than old experimental Fathead main. Who made the main?

That rubber block at head shackle looks like what is used for push up luffs, it isn't push up is it?

Must say, it looks like the type of head I was interested in putting on a Mossie, until I did the "Altered" thing.

Regards Gary.

Hi Guys
I'm also very interested to find out how the mossie will perform with a fat head main. So far from what I have read you chaps in Oz have been against the idea since the initial experiment which was not to succesful as I understand it.

We in S Africa have spent many hours, days, weekends over many many beers talking on this subject. The one idea (I like) is to bring the mosquito into line as to what is happening currently with all the other cat classes on the market.

Introduce the fat head main, make the boom shorter so that sheeting of the main will be off the clew of the main. Boom can then be lighter. Still keep the same sail area. I'm sure that this type of sail shape will perform beter over a wider wind range (6 to 25 Knots) as opposed to the old pin head shape over the same wind range, which is the range of wind we normaly race in.

Hi Sarel

I wasn't in Mosquitoes at the time, but from what I heard the experiment with the square top sail was very successful. The people who tried it out liked it, some claimed it made the boat easier to handle in a strong breeze and it looked good. It wasn't shown to be any faster at that stage, which was another point in it's favour (it wouldn't make the old sails instantly obsolete).

Sadly it didn't become the sail we all use today, but it sounds like that was because in the end a majority were persuaded that it would be bad for the class overall. Many threatened to leave the class if it was adopted.

It's easy to see now (20/20 hindsight!) that those concerns were wrong, as the sail wasn't changed and the class virtually came to a standstill anyway while the Mozzie owners switched to Taipans and sailing became less popular in general. The square top would have served the Mosquito well over the last 12-14 years if we'd had it.

The situation now is a little different. The sail that was being considered then worked ok on the existing mast, but would now look just as out-of-date as the current sail. The square top sail that would be considered these days is more radical than 14 years ago and there's serious doubts that our very lightweight mast will do the job. It will be interesting to see the results of your experiments with the short boom.

The other important thing to remember is that rather than being in crisis control mode, the class is actually growing now. You have to think about what it is about Mosquitos that's attracting people to the class - and be very careful not to mess that up. Right now the Mosquito has some unique features among the catamaran classes (eg. performance for the cost, easiest cat to handle a spinnaker, easy to handle out of the water and fast in everything from a drifter to survival). There's no point blindly making the Mosquito like other catamaran classes if that just makes the Mosquito irrelevant.

I can understand why you guys in SA want to make your Mosquitoes faster, but there is a simpler way, with all the design, testing and research already done for you. It's only a small change, but the next Mosquito you build, use a set of Taipan plans instead.