Twas a bit of a lottery for the first couple of hours as there was NO wind.

Then the wind was in just the wrong place for a single handed F16 I could not carry the kite on 5 legs much - even with the traveller all the way out, as little mainsheet tension as I dared, I was still sailing much too low and going up the beach, so I tried kite up / drop it / head back up / put it back up, but this was not too quick, but all the 2 up boats could twin string and carry the kite. I was in with the Tornado's at Bradwell, but then all the other boats just sailed past twin wiring with the kite up that I could not carry - <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />

I'm just praying for the year when it's the right angle for a single handed kite boat <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Next years race in 13th July <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I measured this stuff yesterday when I played around with retrimming my mainsail in order to catch our class chairman Hans in the next club race !

From fully untensioned after hoisting to flat sail all over and a tight downhaul/mainsheet I go from number 2 to number 8 on the magic marine stickers that have a spacing of one inch between the numbers (= 25 mm). So I do travel 6 inches = 150 mm. However when sailing I start at number 5 when having a slack downhaul and a modestly set mainsheet. so halve the travel length is caused by the mainsheet alone already and another 3 inches is pulled to flatten out the mainsail by pulling both tight.

In order to flatten my mainsail I have to play the mast rotation setting. I can't get it too flatten as in the pictures in Geerts post with playing the mainsheet and downhaul alone. But that maybe just my mainsail (and other Redhead mainsails)

Wouter

Si, I don't want appear to be on your case but I obviously have different views on sailing than you. When you mention lots of downhaul and then more. Once a sail is flat more downhaul can't make it flatter? And this thing about having to be on the wire to sail low with the kite up. I don't get that either. T's & F18's only single wire downwind and A's can't be fussed at all. But don't let me stop you because one day F16's will be the fastest single handed small boats on the planet. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> Damn!! I forgot you can sail them two up as well.

I agree you can only flatten a sail so far, just most people I see don't flatten the mainsail fully.

How much DH do you see in windsurfer sails, most I see are very twisted off having had loads of DH applied. They must be doing it for some reason.

There is a "sweet" spot downhill where the extra righting moment (RM) of someone on the wire creates more speed, this moves apparent forward and allows you to go lower. Too much RM and you cannot "get a hull up" and so loose the drag of the hull. It's a magic balancing act of heading, vs speed and the need to get the hull up in the air to go fast downwind. Taking of T's; 1 wiring on the T is approx the same as 2 wiring on 8 foot wide cats.....Somethinbg to thinnk about for the 8 foot wide boats with big kites..........

Talking to some of the A sailors at the ECPR, one in particular said on this very subject that they are starting to try wiring down hill in the bigger stuff.

About double trapping downwind on the T. You got to find the best VMG, and for pure downwind sailing in the big stuff it is with one on the wire and one on the tramp (or hull). In a distance race however, the angles and VMG might be best with the kite up and two on the wire. The T kite is so flat that you can build some really serious apparant wind. Boat feels like it is skipping over waves, but you are balancing on a thin edge. A sudden lull is enough to capsize the boat over yourself. Quite fun to look on when a crew pulls the boat over themself..
Having just the crew on the wire also make it easier/faster to manouver, which might just be the thing in a large regatta.


These guys seem to think double trapping under spi is fast <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

(but the mainsail looks a bit flat in the top. Perhaps their downhaul is maxed <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> )

I would not bring windsurfers into this downhaul discussion. Their requirements are a bit different than for catamarans and they have some quite specialized sails and masts for course racing, wave etc.

I was only told last week that they are twisted off so much to give a faster flow on the lower part of the sail.