Don't forget to include the crewweight.

I-17 R solo = 225 kg overall
F16 solo = 180 kg overall

Ratio = 225/180 = 1.25 % heavier instead of the 46 % that you gave.

I wouldn't get a different main for your boat untill you've sailed the standard one a few times in high winds. With a properly cut main and the right trim actions you may find there is not need.



I-17R versus F16 ; the question


I think the I-17 R is everything the owners claim it to be (with the exception of the issue around weight). Brobu is very happy with and he is up to speed with it. By all means it is a good boat. I feel a little funny about nacra using the F18 boards for the I-17 especially since its righting is so different as a singlehander. I think both the I-17R and F16 in solo setup will notice the lack in momemtum in relation to doublehanders.

The F16 and especially the newer ones are all we hoped they would be (to bad I can't quote the test results but may the lord strike me down if I'm lying or deceiving here). One example I can give Geert (Taipan sailor in NL) was T-boned lats september by a Hobie Tiger with considerable speed and the damage was a crack, not a hole, just a crack that he fixed with a piece of tape to complete the regatta. His boat is now in repair. These lightweight babies are not fragile.
There isn't much difference between the I-17R and F16 in controls and trim tools. There may be some difference in momentum but with less drag the F16 need less momentum to continue as well. 25 % may sound like alot but it the low drag may well nullify this difference. Formulae roughly suggest that the I-17R has 10 % more water friction drag for given speed as well.(there are more forms of drag so the total may be more)

I seriously suspect that the difference between I-17R and F16 may be small indeed if at all noticeable. I'm conservative so lets assume it is noticable under specific conditions with large waves and no wind (not very regulary encountered)

On the otherhand. I-17 R sail area is only slightly less than 10 % more than the F16 and its mast is only 7 % longer.

When looking at the drags I suspect the F16 to have the edge in flat water and light winds conditions (more frequently encountered)

These differences will always remain between designs. Just decide which you think it most important.

With respect to controllability in heavy air. There is either no difference (righting ratios) or the edge is slighlty towards the F16 because of lower sheetloads and the generally shorter boards (less tripping). I for one have never heard or experienced the Taipan becoming difficult in heavy winds.

Wouter