>>Finally, the High aspect jibs on the Tornado and I 20 are useless going downwind alone without a chute. (That's why
you will see the I20's avoid hot reaches to sail high and then pop the chute to get down on odd ball courses.)


I don't fully agree here.

The selftacker may be less efficient on the downwinders but never useless. "Useless" suggests that you can just as well saile without it on the downwinders and that is certainly not true. Also I very much believe the reason for the loss of a little speed on the downwinders is to be found in the cut of the selftacker jibs. Selftackers are still exclusively used on spi boats and here the jibs are complete cut to optimized upwind sailing by sarcrifising the reach and downwind performance when sailing without a jib. This all has nothing to do with being high aspected or not not even with the selftacker setup itself. It is a direct result of the flatter cut od these spis when compared to jib on non spi boats.

I found signs for this on some personal experiences between my Taipan F16 and standard Taipans. Especially since me first jib was cut a little to full for a spi boat. It would collapse when I pointed with the standard Taipans and so I lost there. However on reaches and downwinders I was quite alright. Only on deep downwinders the standard boats gained ever so slowly on me. I won't go into details. Experience gained during touring stages of this summers DCC in 4 - 14 knots of wind.

The specs of the boats were

Standard Taipan

jib 4.15
main 14.56

total 18,71 sq. mtr.

Taipan F16
jib 3.45 sq.mtr (May be larger under F16 rules but construction limits prevent this)
Main 14.85

Total 18.30 sq. mtr.


So I was sailing with 0.41 sq. mtr. (4.5 sq. ft.) less area in total.

I'm recut the luff curve and I think I gained upwind performance against some loss on the downwind legs. I think the reaches will still be relatively all right maybe a small loss here.

If anything, we can take away from this that entlarging the square-top and putting a selftacker on can result in about the same performance as the overlapping jibbed boat with a pinhead main. Actually I found the differences to be so small that they may all be caused by errors in trim and balance. I know for certain that I sailed the DCC event with to much prebend and the middle section of my mainsail wasn't working optimally. I saw the tell tales in the middle do funny things but only realized in the last week what the cause had to be.

Wouter