At speed, how do you think drag distributes above water (body, board, etc...) vs below water (submerged foil)?
Saw an analysis of speed windsurfing (50 knots) saying drag was 40% sail, 30% sailor, 20% board, 10% fin
The ART foils are like a shrunk pump wing, they are quite thick which limits top speed.
Good glide and pump at their efficient speed though.
I'm not sure you got it right regarding the thickness of the ART wings. I'd like to see some comparative specs because the three that I owned seemed quite thin.
They run a 14-15% airfoil, most others are <12% or even <10%
The short chord make them seem thin but it's the percentage that really matters.
The Fanatic Aero Free 800 is pretty fast here I'm doing 23mph flagged out this morning. May have gone faster will check rear of vid. video will be up on my Insta later @pastyadventures & full video on YouTube from this weeks winging soon

At speed, how do you think drag distributes above water (body, board, etc...) vs below water (submerged foil)?
Saw an analysis of speed windsurfing (50 knots) saying drag was 40% sail, 30% sailor, 20% board, 10% fin
I remember people were using single-sided booms for awhile... don't know if they're still doing that or not.
Sabfoil has updated their range. Part of the update is specifically aimed at speed, and includes race specific masts, fuselages, front wings and stabs.
according to their website three front wings are capable of speeds above 30 knots (for 75kg rider).
check the Red Devil serie (596 and 636) or the blade 671.
The Fanatic Aero Free 800 is pretty fast here I'm doing 23mph flagged out this morning. May have gone faster will check rear of vid. video will be up on my Insta later @pastyadventures & full video on YouTube from this weeks winging soon

I'll get the TE mast next... will see if it's any faster. This is on the regular 90cm carbon mast, 68cm fuselage, Aero Free 1000/216. I have a 60cm fuselage set up with the 800, but haven't had a chance to get out on it yet.

UPDATE:
Thanks for all the tips and comments so far.
I took the plunge and etch primed my mast and sanded to 800 grit with the flow of water. No ventilation today and my best speeds. Over 22knots.
500m run Ave 20knots / max 22.9 knots. Cruising at 20knots is pretty easy now.(Art 899 / standard fuse / 370 freeride tail with -ve shim).Next gotta dial in the progressive tail (which I find much more unstable over 20 knots)

I'll get the TE mast next... will see if it's any faster. This is on the regular 90cm carbon mast, 68cm fuselage, Aero Free 1000/216. I have a 60cm fuselage set up with the 800, but haven't had a chance to get out on it yet.

Sunsetsailboards that is fast!
I'll get the TE mast next... will see if it's any faster. This is on the regular 90cm carbon mast, 68cm fuselage, Aero Free 1000/216. I have a 60cm fuselage set up with the 800, but haven't had a chance to get out on it yet.

Sunsetsailboards that is fast!
hah that is a momentary blip (why I chose it) but the 10sec average on that reach was a respectable 23.2 knots (26.7 mph) as reported by waterspeed.app via Apple Watch. Watch and GoPro seem to report similarly, although the GoPro goes haywire for a bit if it gets submerged
r0d awesome that a little tuning resulted in some gains!
And if you're on Android get the Windsport Tracker app, it calls out your speeds which is an awesome training aid. You can set the minimum threshold too. Accuracy will depend on your phone but on my Motorola G62 speeds are very similar to Apple Watch SE. Uses the differential gps algorithm for speed which is supposed to be the way to go.
Top race guys are getting over 30 knots. I've hit 26 knots a couple of times on my Cabrinha H650, that was sketchy enough.

What GPS site is this screenshot from? Thanks!!
Best way to increase your "measured speed" is to use a non Doppler GPS device . The windsurfers will know what I mean :-)
Top race guys are getting over 30 knots. I've hit 26 knots a couple of times on my Cabrinha H650, that was sketchy enough.

What GPS site is this screenshot from? Thanks!!
It's from the Salmon app I think. They make a device for measuring speed
Sabfoil has updated their range. Part of the update is specifically aimed at speed, and includes race specific masts, fuselages, front wings and stabs.
according to their website three front wings are capable of speeds above 30 knots (for 75kg rider).
check the Red Devil serie (596 and 636) or the blade 671.
I spent some time trying to go fast on the SAB W800 and my best was 25.7 kts for 5+ secs. On the W1000 my best was 23.3 kts for 6 secs. Quite slow. S399 rear foil. M103 mast. And a few crashes in the process. The W800 seems to hit a drag barrier so I'm not sure how the kite guys do > 30 kts on the W800. Using my Naish 914 with GPS a few times I did 27 to 27.5 kts for 5 to 12 secs, with a C100-85cm mast, so that foil does alright if you bring it up near the surface.
I recently cut down my W1000 into the "WE900" and my W800 cut down to become the "WE730". With both foils I've removed the negative twist in the tips which I guess was holding them back. I've not used my cut-down W800 yet, but I twice used the cut-down W1000 in 6-10 kts and it feels really nice and did just over 22 kts briefly in ~ 10 kt gusts, so hopefully this version can do over 25 kts. I'm hoping the cut-down W800 will do 28 kts, but who knows. I was so happy with the cut-down W1000 that I also cut-down my Naish 914 just a little (15mm per side) to remove some negative twist it has, and try get a bit more out of it.