Macquarie Innovation Takes Class D Record: 48.14 knots

And did it 1/6/09 in 17 knots of wind! The ratio of boat speed/wind speed being the highest of all the speed sailers-2.83. For comparision, Hydropteres ratio is 1.3-1.6 . And boards and kites are considerably lower than Hydroptere.
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Perhaps the real measure of "speed SAILING" should be a formula that takes this ratio AND speed into account. What do you think?
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edit: just noticed I had posted windspeed/boat speed-wrong! Corrected now! Sorry!
and I forgot this-geez: http://www.macquarie.com.au/speedsailing/design.htm

[Gary Baigent]

48 knots in 17 knots breeze. - that is all class - nothing else comes close to that ratio and yes, why not make this a new type of record.

[Tcubed]

I have long been of the sentiment that V/W is far more relevant than just V.

So thanks Doug for raising the point.

After all what's from building a foiler out of solid titanium (sails and all) and sailing it in a category 5 hurricane? Definitely get past the 100 knot mark like that, once the cavitation and control issues are worked out (and recruiting the berserk pilot of course)

[chabrenas]

Tcubed: your hurricane would have to come up pretty fast to keep the waves down to what such a craft could handle, but it does illustrate Doug's point. As speed records continue (like other aspects of sailing) to attract wider publicity, maybe enough sponsors will join in to make it possible to have a V/W category as well as a raw speed one. I doubt the raw speed one would ever go away, though.

[Tcubed]

In such hypothetical situation the same criteria would be applied to the sailing site as is currently used, namely protected water with unimpeded wind. In such extreme winds with very little fetch the water does not really build up waves so much as disintegrate into a continuous gradient of fine whipping spray. Really i think in such extreme conditions the main problem for control is severe large scale wind turbulence (severe gusts).

[chabrenas]

Good point, Tcubed. The videos I've seen (Hurricane Andrew, for one) make it very clear that flow is highly turbulent if there are buildings and other obstructions around, but I'd guess that even in a flat open space the air could be full of vortices with a horizontal axis (i.e. rolling along the surface).

But there's also the possibility of the wind blowing half the water out of your shallow pan before you can get a good timed run in (:=> .

[Tcubed]

Yes, the Reynolds number is high thus there is a lot of turbulence even with a flat terrain topography. The wind becomes 'lumpy' and erratic which combined with the brute force of it makes for very challenging conditions to operate in.

I was not thinking shallow water , but yes one would have to take into account the storm surge and the effect of wind blowing water away from the protecting land.

Also one would have to take into consideration the aeration in the water and the increased air density due to all the entrained water particles.

All this might seem beyond absurd fantasy-land, but judging by the incredible lengths people go to to break records i would not be surprised to see something of this sort being played with in a few years.

[chabrenas]

Mentioning aeration brings to mind the problems of huge gas leaks that have sometimes happened with undersea drilling. Bit of a bummer if your foiler sank instead of flying...

But you're right - particularly if the game starts to attract either big commercial sponsors or the egos of America's Cup challengers.

[Ilan Voyager]

Lindsay Cunningham rules again, the experience gained with the C class catamaran pays. An apparently simple design with tons of clever brain juice...that's achievement.
And as said Doug Lord a ratio wind speed/boat speed almost unbelievable. You have put the finger on a very good point; this ratio measures the efficiency of the design.

Have you remarked that 2 of the best designs in their category (Idec for circum-navigation world record, Macquarie for speed record) look so deceptively simple?