No comparisons from my side of the pont as spi boats and non-spi boats are nearly always seperated over two different race fields. Meaning they don't even sail the same courses. The races were we do all sail together are often distance races or something and here the comparisons can be quite skewed.

With regard to the sloop an uni comparison. There are a few things to consider here. But first let me give you the quick run down of how the Sloop-uni specs in F16 came to be.

-1- We knew that the Taipan 4.9 sloop was faster around the course then the Taipan uni. The comments were that on relatively short courses or when involving relative many manouvres (tacks etc) the uni could keep up with the sloop due to its better ability to make quick manouvres. It also could point higher and as long as there were no double trapeze conditions the Uni sailors could get maximum saildrive as could the sloop sailors. When going on the downwind the sloop would have an advantage.

what did we do. We took this situation and tried to make it less significant by :

- adding a spi to both , this makes the jib far less important on the downwind and should bring the tw0 closer to eachother on the downwind.

- Make the mainsail larger with respect to the jib, this means the uni loses less saildrive as a result of not having the jib while the overall speed of the sloop would stay the same (more mainsail area for less jib area)

- Make the boat wider, this would help the singlehander sailor by allowing him to delay the act of depowering. It delayed the cut off point where the sloop can still generate more power while the uni has to depower. The additional power of the sloop was probably limited as the mast and sails would flex before more saildrive could be developped, at least that was a consideration that played in the decision. However I think its lightweather effect (more area of the uni = more speed) is far more significant.

- Open sailplan allowing larger square tops. This allows the sail design to be adjusted more to singlehanded sailing meaning the sail twist of better and react better in the gusts. This has now shown to be the case; several of us have experienced this happening


Having said this there are a few inequalities that we simply can not solve. And thus we know we could get the two boat to perform pretty much the same but never perfectly equally.

-1- Righting moment differences wiil always remain. The doublehanded version can just create 200 % of the righting moment as the singlehanded version can. This means that teh saildrive on the doublehander will continue to grow when nearing the double trapeze conditions when that of the singlehander can not. This phenomenon is often seen between the A-cats or F20's and the F18's as well. Any difference (or equality) there was in the lower halve of the wind speed vanished in the upper halve of the windspeed.

-2- A doublehanded crew can just sail the boat more on the edge than a singlehanded crew can. There are just more hands to trim the sails and to make emergency interventions when needed. So even if the singlehanded has the advantage of quick manouvres , the doublehanded crews have a forte on outright boatspeed. This we also knew from the Taipan sloop and Taipan uni situation. Therefor it was commented that the uni likes shorter courses where the doublehander can not really stretch its legs. And visa versa.

To compensate a little for point 2 above we allowed the F16 uni to be rated faster than the F16 sloop. So we allowed the uni, in mathematical models, to have a theoretical higher boatspeed than the sloop. This way we hope than higher speed and less "edgy control" will compensate eachother to a point closer to the doublehanded setup. As a matter of fact the F16 uni has a texel rating of 101 (and was rounded upwards) while the F16 sloop has 102 (rounded off downward). This is different from the Taipan 4.9 uni vs sloop situation (that Eric comments on) which is the other way around. We allowed this rating skewedness to develop also as my personal opinion is that Texel has an offset when it comes down to lightweight singlehanders and the offsets are about 1-2 %. So we skewed the ratings by about 1.4 % = 50 seconds/hour. This way we can at least race first in wins as F16's among ourselfs which was the more important goal than having the same Texel rating for both setups. Sadly the ISAF / SCHRS rating system has an even larger ofset in these cases and that is beyond correction. OF course this is the same handicap problem that the A-cat class has, although in their case it is even more pronounced. Afterall we knew what we were getting into and could optimize the rules to favour us a little more in the ratings.

The comparison Uni - sloop in real life will always be skewed that is a given and we accept that. However I'm quite convinced that the F16 rules will have made the uni and sloop the most comparable in speed of all possible setups using the same hardware. We did actually work hard on this. I think we are at least comparable enough to race first in wins on an acceptable basis; meaning that sailor skill is still 10 times more important than the limits of strongpoints of the particular setup that a crew is sailing. This is enough for fun sailing and most racing.

With regard to F16 vs A-cats :

We knew from the Taipan that the 4.9 uni's (no spi) were comparable to middle fleet to sub top A-cats. We tried to correct this by :

-1- adding the spinnaker; most important part and in my view makes the F16 faster around the course than the A
-2- Adding width. This makes the F16 uni 2 % faster upwind than the Taipan uni which reduces the gap between it and the A's
-3- Enlarging the mainsail from 14.58 to 14.85 (2 % increase) all going to the larger squaretop. Improves gust response and hopefully adds a little speed as well.

I think Eric has points 1 and 3 when he sails but not point 2 (extra width) he is currently sailing at the same width as the A's.


From looking at the results Eric supplied and the results of some tests that were performed I see signs that we are closing the gap to the A's by these modifications. And I trully expect the F16's to be more competive to the A's upwind than before (Taipan 4.9 uni). The spinnaker is all inequality downwind, I know, but as that favours us and keeps us close to 2-up F16's and the F18's so I don't worry about this at all. Afterall we are after the best compromise given many conflicting wishes sailors may have, not after being to fastest singlehander or best in any way. Also I think the A's will eventually go for spi's as well; if they don't than I do think the F16 uni's will proof to dethrone the A's as the fastest singlehander after the 18 squares which are arguably dead as a class.

In my opinion the A-cat will always be the better design upwind, even though the difference may be reduced to "small" indeed. I also think that its relatively slow downwind leg will allow other designs to beat it to the finish line. I think the F16 1-up fits this bill nicely by not losing to much on the upwind leg and win back alot more than needed to compensate for the upwind leg when spinnakering downwind. After 2 or 3 rounds the F16 should edge herself in front. That is of course when the crew is comfortable enough with the spi; it will take more skill to sail the F16 over sailing the A, that will also be true. But that I think is a good thing in itself.

I trully think we made the best decision when focussing on creating the best compromise over being the best in one or two aspects. Now the other classes can adds mods to themselfs , like the A's getting a spi but they still will have a hard time taking on the flexibility of the F16's. You don't convert an A-cat that easily to doublehanded sailing. And if you would do that then you would probably end up with the same performance or even less than the 16's. It will be quite a feature to better the F16's when it comes down to the trio of flexibility, low cost and serious performance.

A lengthy post but I though that this background info would be of interest to us all. I used your post to attach it too but it is definately a post for all and I felt like this was a good time to write it down.

Wouter