Forums > Windsurfing   Gps and Speed talk

Sebastien Cattelan hit a VMax of 61.7kts

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Created by Chipmunk > 9 months ago, 29 Oct 2009
Chipmunk
33 posts
29 Oct 2009 9:28PM
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From Rob Munro

Wow! Luderitz went off the scale today and so did the internet!!!

Massive winds hit 2nd Lagoon today during the warm up to the Luderitz Speed challenge 2009! Not only were potential GPS records set and broken, but the wind took out the internet dish and the whole of the Luderitz area is now official cyber-blacked out!

BUT, the information via old-school-comms, the telephone is simply insane.... Sebastien Cattelan hit a VMax of 61.7kts and, subject to ratification, has set a new Record for the 10 Second average of 56.5kts including a 56.8 10 Second run and an even more important 53.058kts 500m just before the official start of the WSSRC event!... Read more

Hennie Bredenkamp and Basil Cambanis were on hand, as well as World Kitespeed Record holders Alex Caizergues and Sjoulkje Bredenkamp, who all went out in some serious winds hitting 48kts! Alex and Hennie were touching on the 58's VMax with 53's on the 10 second runs, but Hennie, who borrowed a new Bandit promptly destroyed it after his 2nd run, with what he muted as his "worst beating for years," went on to to Diaz Point with his sailboard, but couldn't keep the tail down using a 4.2 Stealth! Manu Taub trashed an 8m Bandit, Sophie has damaged her ankle and most were on the sidelines watching the day unfold due to the super strong winds. Sjoukje's 4.5m was too much to risk and Charlotte was tip-toeing down the strip. Luderitz showed it's teeth today and all are hoping for more to come!

Winds were solid all day, with a good angle, but spin drift and more, didn't stop Seb from using a 9m kite in winds close to 50 knots! What is to come for the month ahead??? Who knows, but it has certainly been preempted by major and World beating GPS speeds so far (subject to ratification!)

Keep an eye on www.gps-kitesurfing.com for sessions being posted and on www.luderitzspeed.com for all of the news from Luderitz (once the internet has been restored!)

Regards

Rob
http://www.facebook.com/profile.php?id= ... nge?ref=mf

Sorry No Windsurfing info yet
Mike Pacey

Genetrix
SA, 236 posts
30 Oct 2009 8:57AM
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so wish i could be there, catman will take the record Iam sure of it this year.

mathew
QLD, 2133 posts
30 Oct 2009 2:52PM
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www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=56628

Jethrow
NSW, 1272 posts
30 Oct 2009 8:26PM
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You can say what you want about the boardies over the wetsuit crowd but that is bloody fast...

wkcwarrior
371 posts
30 Oct 2009 7:55PM
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hrm 62 knots of max ????
maybe it is time for us to use 4cm speed fins, or ?
so, let the kiters feels happy about that.
for me, kite it is different sport, and every sport need to have its records
so far we know who is the fastest windsurfer, are we?

Windhogger
SA, 88 posts
31 Oct 2009 9:22PM
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Here's Sebs 60+knt run.

elmo
WA, 8868 posts
31 Oct 2009 7:16PM
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Sheeet that's hammering

choco
SA, 4175 posts
1 Nov 2009 8:09AM
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elmo said...

Sheeet that's hammering


I'll second that!

Give the kiters another 5 years to further develope their boards/kites and 70knts would be within reach.

56.02 knots ( 56.87 56.76 56.51 56.17 53.78 )
Max. GPS (display) 61.79 knots
Max. 2 sec. (software) 61.25 knots
100 m run 59.85 knots
250 m run 57.26 knots
500 m run 52.93 knots
Nautical mile 15 knots

Goo Screw
VIC, 269 posts
1 Nov 2009 10:02AM
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With all other sailing craft the rig and the board are measured as one unit.
The gps speeds we get from the Kites only appear to measure the speed of the craft(sailor) and not the rig(kite) which appears to be a long distance in front(at the start).
So when they are doing timing gates for the official record do they start timing as the first part of the rig goes through the start and finish timing as the last part of the craft or rig goes past the finishing gate?

elmo
WA, 8868 posts
1 Nov 2009 7:43AM
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The gates are at water level (or just above) so they measure what goes through them, they are generaly(?) linked to Video so there's little room for mistakes

Goo Screw
VIC, 269 posts
1 Nov 2009 11:09AM
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elmo said...

The gates are at water level (or just above) so they measure what goes through them, they are generaly(?) linked to Video so there's little room for mistakes


If this is the case and the gates only get the board and rider and miss the rig all together,then I hope that they can raise their line of sight to put the Kites on a level playing field!

nebbian
WA, 6277 posts
1 Nov 2009 8:44AM
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Goo Screw said...
So when they are doing timing gates for the official record do they start timing as the first part of the rig goes through the start and finish timing as the last part of the craft or rig goes past the finishing gate?


I would have thunk that you measure from the same point on the craft, whether you're starting or finishing.

Many systems use a light beam at the start gate, that starts when it's interrupted... and the finish gate has a beam that stops the clock when the beam is interrupted.

So no matter what part of the craft hits the beam, it should be the same part for both gates, which will give you a pretty good indication of its speed.

If you have to wait till the whole craft goes through the gate before stopping then you'll have an inaccurate measure of its speed.

Goo Screw
VIC, 269 posts
1 Nov 2009 2:42PM
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nebbian said...

Goo Screw said...
So when they are doing timing gates for the official record do they start timing as the first part of the rig goes through the start and finish timing as the last part of the craft or rig goes past the finishing gate?


I would have thunk that you measure from the same point on the craft, whether you're starting or finishing.

Many systems use a light beam at the start gate, that starts when it's interrupted... and the finish gate has a beam that stops the clock when the beam is interrupted.

So no matter what part of the craft hits the beam, it should be the same part for both gates, which will give you a pretty good indication of its speed.

If you have to wait till the whole craft goes through the gate before stopping then you'll have an inaccurate measure of its speed.


If that is the case,shouldn't the first thing to pass the start - finish gate (the front edge of the kite) start and finish the timing? ...rather than having some portion of your "yacht" well into the coarse before timing begins??

mathew
QLD, 2133 posts
1 Nov 2009 2:02PM
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nebbian said...
I would have thunk that you measure from the same point on the craft, whether you're starting or finishing.


Its a bit more complicated than that... For most sailing craft (lets assume that kitesurfing is actaully a form of sailing), the propulsion mechanism needs to travel at about the same speed as the craft itself, where as with kites, that's not necessarily the case.

Consider this - with a Vmax of 61kn and a V500 of 53, then for some part of the 500m course, they are hitting close to 40m/s for a few seconds and (only!) travelling at about 40-45kn for the other half of the run. So the question -> why the variation?

Without any other evidence, we could assume of the following:
- kites suffer from insufficient lead-in distance for the currently used courses,
- the kite is being used as part slingslot for the rider,
- video & light timing usually doesn't measure the complete vessel (compared with most other sailing craft).
- etc.

I'm not saying anything postive or negative about the topic specifically -> its very quick... my last "get off" at only 40kn, cracked/brusied a rib... just that comparing apples to oranges is not necessarily valid, without *also* specifying the constraints.

stamp
QLD, 2791 posts
1 Nov 2009 2:50PM
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mathew said...

Select to expand quote

the propulsion mechanism needs to travel at about the same speed as the craft itself, where as with kites, that's not necessarily the case.



Without any other evidence, we could assume of the following:

- the kite is being used as part slingslot for the rider




this makes no sense at all. what are you basing these assumptions on? can you explain this "slingshot theory" of yours, and also how exactly the kite travels at a different speed to the rider.

have you invented a new set of physics laws, or is it just the sour grapes theory applied once again to speedsailing?

Goo Screw
VIC, 269 posts
1 Nov 2009 3:59PM
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stamp said...

mathew said...

Select to expand quote

the propulsion mechanism needs to travel at about the same speed as the craft itself, where as with kites, that's not necessarily the case.



Without any other evidence, we could assume of the following:

- the kite is being used as part slingslot for the rider




this makes no sense at all. what are you basing these assumptions on? can you explain this "slingshot theory" of yours, and also how exactly the kite travels at a different speed to the rider.

have you invented a new set of physics laws, or is it just the sour grapes theory applied once again to speedsailing?




This type of potential "slingshot" or shortening of total craft length(by bringing the sail back beside the rider while in the coarse) problem should be avoidable by simply starting timing as the front of the kite goes past the starting gate.

stamp
QLD, 2791 posts
1 Nov 2009 3:25PM
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?

mathew
QLD, 2133 posts
1 Nov 2009 3:31PM
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stamp said...
this makes no sense at all. what are you basing these assumptions on?


not sure what you mean by this - to travel 500m + have a 61kn peak, half of the run *must* travel somewhat below the 53kn avg.


can you explain this "slingshot theory" of yours, and also how exactly the kite travels at a different speed to the rider.


This has been discussed to death... have a look on this forum or on the GPSSS forum. The short of it is that it is possible to measure this effect by putting a GPS on the kit, and I think Tillman has even done so, but I cant remember what the result was.


have you invented a new set of physics laws, or is it just the sour grapes theory applied once again to speedsailing?


no sour grapes - you obviously chose ot ignore my recognition of "going fast".

Kiters are very fast - kites usually have power to burn, so kiters are all likelyhood overcoming some of the high-speed drag, and it appears that they are making use of "super-ventilation" (although I'm probably miskten about that), which is something that I cant see windsurinfg making use of.

mr love
VIC, 2401 posts
1 Nov 2009 4:48PM
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My attempt at an explaination of the "slingshot"effect Gooscrew is refering to is to compare it s to being whipped around a corner when waterskiing. You are travelling considerably faster than the boat that is towing you.
The implication is that you "slingshot" around the Kite that is towing you and are therefore moving faster than the kite.

So if this is correct the rider can travel the 500 meters faster than the kite.

Am I correct in my explanation gooscrew?

Goo Screw
VIC, 269 posts
1 Nov 2009 4:56PM
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mr love said...

My attempt at an explaination of the "slingshot"effect Gooscrew is refering to is to compare it s to being whipped around a corner when waterskiing. You are travelling considerably faster than the boat that is towing you.
The implication is that you "slingshot" around the Kite that is towing you and are therefore moving faster than the kite.

So if this is correct the rider can travel the 500 meters faster than the kite.

Am I correct in my explanation gooscrew?


The main issue is the potential for the rider to be covering the 500 faster than the kite(if the rider is being timed).

Some Physics :- As the sailor increases speed the apparent wind becomes more perpendicular to the true wind so the kite must come back into a tighter sheeting angle.

nebbian
WA, 6277 posts
1 Nov 2009 2:18PM
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Some more physics:

If the kite is considered to the the part of the vessel that is timed, then it would be easy to get an artificially high speed by starting the course with the kite dead downwind, then whipping it forward to the edge of the wind window by the end of the course.

You're far better off by measuring the object with the highest mass (ie the rider).

Goo Screw
VIC, 269 posts
1 Nov 2009 5:36PM
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nebbian said...

Some more physics:

If the kite is considered to the the part of the vessel that is timed, then it would be easy to get an artificially high speed by starting the course with the kite dead downwind, then whipping it forward to the edge of the wind window by the end of the course.

You're far better off by measuring the object with the highest mass (ie the rider).



If some one can start the coarse doing around 5o knots in 40+ knots of wind with their kite dead downwind then good luck I say!!

nebbian
WA, 6277 posts
1 Nov 2009 2:50PM
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Goo Screw said...



If some one can start the coarse doing around 5o knots in 40+ knots of wind with their kite dead downwind then good luck I say!!



Consider this:

250 metre lines, a stunt kite, and a guy treading water in the middle of the course.

I'm sure you can see the problem here.

Goo Screw
VIC, 269 posts
1 Nov 2009 5:55PM
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nebbian said...

Goo Screw said...



If some one can start the coarse doing around 5o knots in 40+ knots of wind with their kite dead downwind then good luck I say!!



Consider this:

250 metre lines, a stunt kite, and a guy treading water in the middle of the course.

I'm sure you can see the problem here.



It comes back to my original point of first part of the "yacht" (as WSSRC put it) to cross the line,meaning you have to start timing as soon as the water treading guy enters the corse.


treedweller
QLD, 59 posts
2 Nov 2009 9:04AM
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Roar
NSW, 471 posts
2 Nov 2009 10:08AM
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Kite boarding is not sailing -
Its wake boarding behind an wind powered aircraft rather than behind a power boat.

eventually the kites will just boost ppl down the 500 meters in the air without even touching the water :)

elmo
WA, 8868 posts
2 Nov 2009 8:59AM
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choco
SA, 4175 posts
2 Nov 2009 11:40AM
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Awesome country side no wonder it gets windy over there,the guys kiting remind me of the speed skiers we get here on the river similar stance/

Dr Funk
NSW, 348 posts
2 Nov 2009 12:21PM
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The guy was travelling 60+knots across the water....that's ballsy and quick. as long as he is powered by the wind I dont think it matters how he got that speed, just a big congrats for getting it. just my opinion.

The Waterboy
VIC, 109 posts
3 Nov 2009 12:48AM
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'Must admit I've gotta say: poor Seb.

He's put so much time & money into running this thing (twice now).

Takes the record in it last year, but is just pipped at the post by another competitor...

..then pulls 60 kn a day or two after the '08 event finishes...

..and now he's pulled a 61.7kn peak, but more importantly a 52.93kn 500m...

...but 4 days too early for it to be official!!!

...I'm guessing only one thing must be going through his head right now; dunno what how it's spelt, but it'd have to be the French version of "D'OH!!",..

.. "D'OH!, D'OH!, D'OH!, D'OH!, D'OH!, D'OH!!, D'OH!, D'OH!, D'OH!, D'OH!, D'OH!!, D'OH!, D'OH!, D'OOOOOOOOOOOOOOOOOOOOH!!!!!!!".

.... poor fella.

Still, the fat lady ain't sung yet; who knows, Wednesday's conditions may crop up for them again while the event's running.

Go Seb.

Dr Speed
68 posts
2 Nov 2009 11:25PM
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why poor ?
He has the official 10-sec-GPS-world-record now, subject to ratification by the WGPSSRC.

























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Forums > Windsurfing   Gps and Speed talk


"Sebastien Cattelan hit a VMax of 61.7kts" started by Chipmunk