Ted,
Couple of questions, as I'm interested in conducting similar tests:
Did you do these comparisons on flatwater, or in waves, and if waves, how did you control for wave conditions? I assume on flatwater you could measure wind speed and assume the current over the same course was rather constant, but wondering how to do this in waves?

How did you control for effort level, as it seems one might tire over the course of several repetitions in one boat, then several in another, etc... or did you do the tests over sufficiently short distances that you think effort was not much of a factor?

How many repetitions did you do in each boat, and how long (distance) was each rep?

Just curious about the boats you mention... you were comparing a 19 inch by 20 foot V10 Sport in Ultra layup with the same boat - V10 Sport - in glass? - and then against the 17 inch V10 in glass and Evo in kevlar (19 inch by 20.5 feet) ... or did I misunderstand?

Cjborg I did'nt get that anal about "testing". These were my feelings of paddling the same areas (flatwater and ocean) day in day out sometimes with GPS sometimes not, like wise 2 boats in the one day or alternate days or weeks. If i consistently give what i think is a max effort and the boat performs a certain way (catching runs, setting a certain time over a flat course and the effect of rebound waves) then thats good enough for me. At the end of the day nearly all the test and reviews of surfskis are only opinions.

Good luck setting up a controlled environment of waves and currents to get more accurate tests done.

I currently paddle a V10S Ultra and a V10 17kg. Previously i had an Evo and was borrowing the above V10, V10 Ultra and infrequently a V10S Performance.

Thanks for the comments- keep them coming.
My impression when I paddled a slightly lighter boat a couple of times was that indeed I did have a bit more fizz in my performance. But is was only a couple of paddles and the conditions weren't 'controlled' in any way.
But think of the opposite situation: when one gets swamped and the footwell and bucket fill with 10 kg's of water, then we all know how sluggish it is to get moving again while the water drains, compared to a dry boat. That's the differnce between 17 and maybe 27kg. Perhaps then the difference between 11 and 17 kg is similarly significant?
Another thought: if anyone ever does really rigorous 'controlled' tests, then they can't be allowed to carry the boat to the water and hence know which one they're about to paddle. In this way the test can be 'blinded' and exclude the 'placebo effect' of knowing you're in a lighter or heavier boat before you start

Hi Gavin
Great thread you started! I believe the very elite (Mr. Borg, Mr. Chalupsky, Mr. Moche and the other elites not mentioned) paddle the lightest, latest and fastest boats made. There performance level is so high and the desire to win so great that maybe it does make a difference what they paddle. Us'en, Bubba the Yardmen paddlers, should "love what we brung" and make sure it is a boat we are very comfortable in (not sure one boat fits all?). I know I want to win, just started racing, but I sure look at the backs of fast paddlers. The fastest paddler's (aerobic/anaerobic, forgot which one it is?) threshold is at or close to their maximum heart rate, so I've heard, (they can paddle wide open for a VERY long time). I can't. I think they could beat the rest of us on a sheet of plywood. I've seen Oscar and his partner Greg paddle on flat water. It was AWESOME!
I bought a light boat because I'm older, fatter and lazier...and I could! Status thing you know?
I'm still not sure, could be wrong, that the $4300 Legend is that much better than the $3200 Legend? Maybe it is?
I go out to eat at fancy restaurants and come away thinking the plate was big but I'm still hungry. I couldn't tell the food was any better (somethings may be in our mind).
That we're paddling and having fun is enough for me...but I hope I beat you there!
Good luck on getting just the right boat!
Franklin

Coming from windsurfing, I've got to wonder if the apparent speed diff between carbon and glass skis is at least partially due to added stiffness, rather than reduced weight.

Rowing research estimates the change in velocity of a rowing shell at 1/6 of the change in total mass. For instance, if a 100 kg paddler switches from a 20 kg ski to a 10 kg ski, then the speed increase would be 110/120=91.6%, difference is 8.4%, so 1/6 of 8.4 would be 1.4% increase in speed. Assuming 7.50 mph on flatwater with the 20 kg ski, the same paddler would do 7.60 mph with the 10 kg ski for the same energy output.

For 80 kg paddler, and going from 15 kg ski to 10 kg ski, 90/95=5.3%. 5.3/6=.88% improvement, so the above gives us a speed change of 7.50 mph to 7.57 mph.

If this is correct, then while racing 7.5 miles at 7.5 mph would take 60 min, racing 7.5 miles at 7.57 mph would take 59 min 45 sec. So, going from a 15 kg ski to a 10 kg ski would save 15 sec per hour for an 80 kg paddler - or thereabouts, according to this estimate.

Throw in waves, accelerations, then the difference in speed might be greater if the paddler is a less skilled wave rider (and has to keep accelerating to catch waves). But, the steadier the speed and the better skilled the paddler in letting the waves accelerate him or her, then the weight difference might not be as much?