With SailGP hitting new top speeds, lessons for our foils?

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Paducah
Paducah
2861 posts
2861 posts
25 Aug 2026 1:33pm
Over the weekend, the French SailGP boat briefly touched almost 58.2 kts. I'm wondering what spillover effects we might see in our corner of the foiling world?

www.sail-world.com/news/299091/France-Set-New-SailGP-Speed-Record

about 1:20 in

utcminusfour
utcminusfour
822 posts
822 posts
25 Aug 2026 10:42pm
Hey Paducah😀

I’m a big SailGP and America’s Cup fan too. Watching their speeds when maybe I’ll reach 20 something knots someday— its comparing different worlds. I have no need to go much over 20 on a foil board, the impacts from falls are too much for me, but I would like to get upwind better so I can ride more waves. I hope we can get some trickle down!

The Cup boats blow my mind with their upwind VMG. They can sail upwind at close to 40 knots, with VMGs in the mid-20s (source ChatGPT). They have enormous righting moment (but only when foiling🙃) and very low aerodynamic drag. Not to mention a huge wing sail that can be deep and cambered or flat and twisted at the push of a button. The crew is faired in and the bustle on the hull just kissing the water. There has got to be more gains available in windfoil by closing the gap with the water through technique and board shaping. To spawn some creative brainstorming thought, what about something sail like below the board? Maybe its leading edge is a ride height wand, and the sail/end plate extends and retracts into the board with wand motion, think sail fish or tuna dorsal?? Okay maybe that's too creative;) The boards with bustles did not seem to catch on but I still feel like there is low fruit there.

The Moth versus iQ comparison is interesting and more to scale. They carry almost the same sail area—8.25 versus 8.0 square meters—but at recent Moth Worlds the top boats reportedly averaged 22–23 knots upwind and exceeded 36 knots downwind, compared with roughly 18 and 29 knots for the iQ. Those numbers are also from ChatGPT, anybody line those two craft up on the water? Now that the iQ can foil tack it's got to be a closer contest. The iQ might have the advantage in marginal foiling conditions using kinetics, but once both are powered, I reckon the Moth should be faster. I know when I see my buddy coming out in his Wasp (sim to Moth) I go look for some flat water to freestyle in rather than line up with him! It would be cool to compare the aero drag (and total drag) between the two (IQ vs Moth), shrouds, spreaders and racks are speed bumps, but the lower half of the sailor should blend into the rack. And the rack gives them more RM. With the iQ the sailor is completely in the wind. The iQ is a one design from years ago, a brilliant design for its time. We need open design coarse racing to push us forward. PWA foil slalom is great to watch but I want gear that can go upwind.

The one thing ALL the boats are doing that we are not; they use adjustable flaps and or adjustable rudder foils to create stable flight with smaller foils. All of them but the silly IMOCA 60's, I don't get why they have not changed their rules yet but that's a rant for another time/forum.

There isn’t much love for the adjustable foil idea in our community, judging by the negative response the topic usually gets on this forum. I get it, I sail at the beach, sand is a nightmare for fiddley ****, but the performance differences are hard to ignore.



kato
kato
VIC
3539 posts
VIC, 3539 posts
26 Aug 2026 7:59am
I’m loving the racing too. I think it comes down to having an excessive amount of horsepower available to use. The foils are still cavitating but they have the power to push a little further into the edges of the envelope. The new foil design has helped too. I noticed in the last race meet the amount of twist that they can tweak into the sails. Amazing for a solid structure.

I always remember a conversation I had with Mal Wright about foil design . He believed that you could build a foil that you could jump on and glide across the water for 50 m or so. That was back in 2004 at Speedweek, way ahead of everyone.
duzzi
duzzi
1131 posts
1131 posts
27 Aug 2026 12:03am
Paducah said..
Over the weekend, the French SailGP boat briefly touched almost 58.2 kts. I'm wondering what spillover effects we might see in our corner of the foiling world?

www.sail-world.com/news/299091/France-Set-New-SailGP-Speed-Record

about 1:20 in




Isn't the 500m speed record at 65.45 knots (121.21 km/h). Set in water conditions seemingly less tame than what shown in the GP video?

Paducah
Paducah
2861 posts
2861 posts
27 Aug 2026 12:56am
First apologies for unintended foil content in the general category. I meant to put it in foiling. Glad to see that I'm not the only one who enjoys watching them race. It can get pretty interesting (eg Canada sneaking through to a second in the finals)

Duzzi, a big difference between Sailgp boats and Sailrocket is that the latter used supercavitating foils - basically just a slim wedge. They work poorly at lower speeds.



source: chevaliertaglang.blogspot.com/2012/12/clearing-50-knot-gate-hydrofoil.html the old Sailrocket website seems to be offline

Subsonic
Subsonic
WA
3443 posts
WA, 3443 posts
28 Aug 2026 3:02pm
utcminusfour said..
Hey Paducah😀

I’m a big SailGP and America’s Cup fan too. Watching their speeds when maybe I’ll reach 20 something knots someday— its comparing different worlds. I have no need to go much over 20 on a foil board, the impacts from falls are too much for me, but I would like to get upwind better so I can ride more waves. I hope we can get some trickle down!

The Cup boats blow my mind with their upwind VMG. They can sail upwind at close to 40 knots, with VMGs in the mid-20s (source ChatGPT). They have enormous righting moment (but only when foiling🙃) and very low aerodynamic drag. Not to mention a huge wing sail that can be deep and cambered or flat and twisted at the push of a button. The crew is faired in and the bustle on the hull just kissing the water. There has got to be more gains available in windfoil by closing the gap with the water through technique and board shaping. To spawn some creative brainstorming thought, what about something sail like below the board? Maybe its leading edge is a ride height wand, and the sail/end plate extends and retracts into the board with wand motion, think sail fish or tuna dorsal?? Okay maybe that's too creative;) The boards with bustles did not seem to catch on but I still feel like there is low fruit there.

The Moth versus iQ comparison is interesting and more to scale. They carry almost the same sail area—8.25 versus 8.0 square meters—but at recent Moth Worlds the top boats reportedly averaged 22–23 knots upwind and exceeded 36 knots downwind, compared with roughly 18 and 29 knots for the iQ. Those numbers are also from ChatGPT, anybody line those two craft up on the water? Now that the iQ can foil tack it's got to be a closer contest. The iQ might have the advantage in marginal foiling conditions using kinetics, but once both are powered, I reckon the Moth should be faster. I know when I see my buddy coming out in his Wasp (sim to Moth) I go look for some flat water to freestyle in rather than line up with him! It would be cool to compare the aero drag (and total drag) between the two (IQ vs Moth), shrouds, spreaders and racks are speed bumps, but the lower half of the sailor should blend into the rack. And the rack gives them more RM. With the iQ the sailor is completely in the wind. The iQ is a one design from years ago, a brilliant design for its time. We need open design coarse racing to push us forward. PWA foil slalom is great to watch but I want gear that can go upwind.

The one thing ALL the boats are doing that we are not; they use adjustable flaps and or adjustable rudder foils to create stable flight with smaller foils. All of them but the silly IMOCA 60's, I don't get why they have not changed their rules yet but that's a rant for another time/forum.

There isn’t much love for the adjustable foil idea in our community, judging by the negative response the topic usually gets on this forum. I get it, I sail at the beach, sand is a nightmare for fiddley ****, but the performance differences are hard to ignore.







I sometimes sail with my moth friends on iq foil (with a formula foil board) generally its a much closer race upwind. Downwind i generally can’t keep up.

you should give your friend on the wazp a race, the current iteration at least is not actually as fast as iq foil. I’ve heard theyre getting upgrades though.

Not sure that the extra notch in speed achieved by the gp50s will see any flow on effects. As amazing as the speeds are, reality is there are some major differences in how they work compared to us that get them up to 50+knots. For sure, the new foils they’re on help to get those extra knots they just got, but we won’t be getting anywhere near their speeds anytime soon/ever. Maybe we’ll see super skinny stainless foil mast bottom ends, but i think thats around about where the flow on designs will end.



Paducah
Paducah
2861 posts
2861 posts
28 Aug 2026 9:08pm
Subsonic said..
I sometimes sail with my moth friends on iq foil (with a formula foil board) generally its a much closer race upwind. Downwind i generally can’t keep up.

you should give your friend on the wazp a race, the current iteration at least is not actually as fast as iq foil. I’ve heard theyre getting upgrades though.

Not sure that the extra notch in speed achieved by the gp50s will see any flow on effects. As amazing as the speeds are, reality is there are some major differences in how they work compared to us that get them up to 50+knots. For sure, the new foils they’re on help to get those extra knots they just got, but we won’t be getting anywhere near their speeds anytime soon/ever. Maybe we’ll see super skinny stainless foil mast bottom ends, but i think thats around about where the flow on designs will end.





I have the misfortune of having to sail around a bunch of really good foiling A-Cats. Their upwind/downwind angles are much better than mine. I'm not a good rep for the windfoil world, though due to my comparatively light weight. The only times I look respectable are downwind on the jibes. Our foiling jibes are much faster than theirs so I can at least get back into the frame. Lightwind upwind really can suck since I often have to bear off to stay on foil. If I come off foil, I become something even an Opti pram can smoke. If they come off foil, they are still an 18 ft cat with very efficient hulls.

Seems like the low salinity of the venue was a contributing factor to the speeds

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