The whole point comes down to the fact wether the ARC products are fast because of efficiency or because of the huge rigs they feature. The problem here is that without having a really comparable design using the "normal setup", it's hard (if not impossible?) to tell wether any speed increase is the result of superior efficiency or just the result of having a bigger engine.

Last year the Dynacat F18 (with planing underside, hard chines, and step) was launched; it didn't make an impression in the F18 class and wasn't seen to beat the "normal" F18 designs. Therefor the conclusion is simple. Now assume that the builder Mattia had put 20 % more sailarea on it, reduced the weight and made it wider as well all resulting in a boat that was a somewhat faster than a standard F18. But how much of the increase in speed was the result of the sailarea, etc and how much of the planing hull ? It is very possible that the planing surface made the hull less efficient and therefor slower while the increase in sailarea, etc was still enough enough to still make the overal design faster. We would never know without a proper reference boat. And the ARC product line is so off in specifications that there is simply no reference boat for any of them.

It appears that all ARC's are underrated in PN despite any outcome of the question above. Bill claims the designs are surprisingly fast in various posts as others, like you, do as well. The SC's are so much more efficient and fast ? Than why is Prindle 18 = 74.5 ; when SC-17 with 13 % more sailarea on taller rig = 73 = 2 % faster. Note also how the SC-17 = 73 = only 4 % faster than a H16 = 76.1 while the SC has no less than 15 % more sailarea than the H16. If anything; the ratings of the SC-17 are remarkably unimpressive considering the rig that sits on it.

Note that the sailarea's of the H16 and P18 are as good as identical. The weigths of both boats are relatively close as well. Increases in waterline therefor can only account for some 2 % speed increase. Please also note that the OLD SC-17 has more sailarea than the F18 = 63.5 as well. So somewhere a significant portion of all that power is lost in order to arrive to ratings that are 11% (spi) to 15 % (no spi) apart. This actually signals inefficiency !


So what is it ? You can't be more efficient and alot slower at the same time. Are the ratings correct and is the setup less efficient because the SC setup only achieves respectively 2 % and 4 % increases in speed for 13 % and 15 %increases in power ? Or is the setup more efficient in addition to having more sailarea and are the PN's are way off ?


The contradiction is not in the complaints but in the claims !

Therefor we can definately "have it both ways".

The refusal to adres this glaring contradiction and camouflage it with lenghty explanations using unprovable claims is the part I named :"smoke and mirrors"

The diaper comments fall fully under the smoke and mirrors description. Or else we must claim that Ellen McArthur can never win a race because she was still in diapers when all other Vendee Globe and mini sat sailors were already winning their first opti races.


Wouter