637 replies to this topic

[WarBird]

What, 60 wasn't enough, greedy bastards, good on ya!

[dolphinmaster]

People are talking about the different types of speed craft that have records and .............. well, when I look at the pics,

I see a kite board, sailboard, cat, proa, wing, foiling, haulass sailcraft. It seems to have elements of everything

that can fly on the water.

Major congrats to the Vestas SR team.

[Reht]

Just read a good interview on clarksail.com where Larso talks a little bit more about the fairings that have made this impressive jump in speed possible. Really interesting stuff; it's pretty amazing how critical small tweaks to the foil package become when the speeds start getting into the scary fast region.

Start getting into the scary fast region? Man, scary fast is in the 20's-30's, these guys are miles beyond scary, I can't even imagine what 65knts under wind power would be like (hell I hardly go that fast in my car most of the time) never mind finding a adjective to describe it.

To put it in perspective, 40 years ago the record was in the high 20s. These days any windsurfer or kitesurfer worth their kit can get there, it doesn't even take more than a few days of practice to get close. I look forward to what we'll have in another 40 years, will we be sailing around at 50+ knts all over the place? Will the record be into the triple digits? With the rate the technology is seemingly being developed it doesn't look like speed sailors are going to plateau any time soon.

Larso and the whole sailrocket crew, good on you guys once again! Keep it going, let's see that 70 fall...

[Tom Ray]

This boat will see the other side of 70 oneday.

A bold prediction. Anyone foolish enough to bet against it? I would not, but would take the other side of the bet.

[Never was]

Well done, all! I hope Helena gets a shot in the next days. Hard to get my mind around what you have done. Fantastic!

[Tunnel Rat]

OK, so Helena has 50.43kts to beat to become the fastest lady over 500m. This record has only been held by windsufers or kitesurfers - never a boat. Have fun!

[auscat]

OK, so Helena has 50.43kts to beat to become the fastest lady over 500m. This record has only been held by windsufers or kitesurfers - never a boat. Have fun!

At 2.5 x windspeed she only needs 20 knts of breeze in 25 knts she could be over 60 have at it girl.

[P Flados]

OK, so Helena has 50.43kts to beat to become the fastest lady over 500m. This record has only been held by windsufers or kitesurfers - never a boat. Have fun!

A Class - Women
1992 Longshot Caroline Ducato USA Brest, FRA 17.81 kts

C Class - Women
1993 Yellow Pages Jean Daddo AUS Sandy Point, AUS 17.38 kts

[Reht]

OK, so Helena has 50.43kts to beat to become the fastest lady over 500m. This record has only been held by windsufers or kitesurfers - never a boat. Have fun!

A Class - Women
1992 Longshot Caroline Ducato USA Brest, FRA 17.81 kts

C Class - Women
1993 Yellow Pages Jean Daddo AUS Sandy Point, AUS 17.38 kts

Then they just need the team lined up on shore blowing in the right general direction...

[Mambo Kings]

"Vestas stock was up 22% in the Danish stock market today!"

And for morons like me who bought in in 2008 (renewables...warm fuzzy feelings and all that crap), that means we just need another 2000% increase and we might see our money back
Not my best call

Try and take the view that your investment helped Chris set a new world speed record and maybe reclaim some of those warm fuzzy feelings.
No ? I guess that didnt work.

[auscat]

I'm sure Larso and crew will be along soon but these shots from face book are just awsome.

Where on Facebook? When I search for "sailrocket", I get two pages but both look inactive.

On his own page.There was also a vid from the plane but that is now listed as private.It sounds like they have been snowed under with media work and working hard to get through it all.It sounds like breaking the record was easy compared to all the attention they are getting now.

[hoom]

Lol, check out the pic that NZ media pulled out of archives
http://www.3news.co.nz/Australian-sets-sailing-speed-record/tabid/415/articleID/277464/Default.aspx

[Sean]

The Weather Channel just showed the record run video! Larso going mainstream media.

[wardy89]

its official!

WSSR Newsletter N0 217. Vestas Sailrocket 2 Outright Sailing Speed Record 27/11/12
The WSSR Council announces the the establishment of a new World Record.

Record: Outright World and World “B” Division Sailing Speed Record
Venue: Walvis Bay. Namibia.
Name: Paul Larsen. AUS.
Equipment: Vestas SailRocket 2. Inclined rig Hydrofoil Proa.
Date: 16^th November 2012. 17.02 hrs
Course length: 500 metres
Current: Nil
Elapsed time: 16.41 secs
Speed: 59.23 kts

Comments: Current Outright Record: 2010. Kite Board. Rob Douglas USA. Luderitz, NAM. 55.65 kts.
Current “B” category record: 2012. Vestas SailRocket. Paul Larsen AUS. Walvis Bay, NAM. 54.08 kts
A further claim for a speed in excess of the above is currently being assessed

John Reed
Secretary to the WSSR Council


now just waiting on the mile and the 65 knot run!!

[trimariner]

I hope by the time they ratify the 65 knot run that they post a 70knotter!!! Hey they jumped 10kts allready, Thats how wonderfully crazy this is! Whew i think I am hyperventilating, or is that hypercavitating? Cheers all. What a Xmas present. Thanks Larso and team and Uncle Vestus.

[Raked aft \\]

Mega Dittos on the props Larso!!

Great going! Knew you had it in you.

Begs my question, the age old adage, 'Bigger is better'

If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??

[nroose]

Mega Dittos on the props Larso!!

Great going! Knew you had it in you.

Begs my question, the age old adage, 'Bigger is better'

If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??

Prolly more complex to scale. And then your logistics prolly scales with volume, which is cube of length, so double the length and 8 times the logistics.

[Raked aft \\]

Mega Dittos on the props Larso!!

Great going! Knew you had it in you.

Begs my question, the age old adage, 'Bigger is better'

If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??

Prolly more complex to scale. And then your logistics prolly scales with volume, which is cube of length, so double the length and 8 times the logistics.

No disagreement on increased complexity, but it may pay in the end.

lets say you double the size/weight of the craft and add 75% to the wing. (which has an exponential increase in power per size)
The net effect is a more robust platform with the ability to handle much higher loads yet still riding on minimum surface area for all the other size/power increases.

Could get crazy fast!

[edt]

"If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??"

If you double the size of the craft you need to make everything four times stronger so it doesn't break in two. Smaller craft have higher top speed but require more wind because they are not as efficient. I think the sailrocket is right in the pocket, it can't get any bigger or it will break.

[Raked aft \\]

"If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??"

If you double the size of the craft you need to make everything four times stronger so it doesn't break in two. Smaller craft have higher top speed but require more wind because they are not as efficient. I think the sailrocket is right in the pocket, it can't get any bigger or it will break.

So make it 4 times stronger, no big deal. I don't know the true numbers, but if you doubled the diameter of a carbon strand rope, you would more than quadruple the strength and just double the weight.

Just looked up amsteel-blue as an example. 1/4" breaking strength 8,600. 1/2" BS 34,000.
This dynamic would apply to all sorts of components on the craft.

if your logic was correct, we wouldn't be seeing 72' winged cats sailing around...

[edt]

"If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??"

If you double the size of the craft you need to make everything four times stronger so it doesn't break in two. Smaller craft have higher top speed but require more wind because they are not as efficient. I think the sailrocket is right in the pocket, it can't get any bigger or it will break.

So make it 4 times stronger, no big deal. I don't know the true numbers, but if you doubled the diameter of a carbon strand rope, you would more than quadruple the strength and just double the weight.

Just looked up amsteel-blue as an example. 1/4" breaking strength 8,600. 1/2" BS 34,000.
This dynamic would apply to all sorts of components on the craft.

if your logic was correct, we wouldn't be seeing 72' winged cats sailing around...

It's not logic its engineering and math. This is why you can make a paper airplane but a glider has to be made out of fiberglass or aluminum. 72' winged cats are right at the edge of our current engineering technology. You can't really make it much bigger with that design.

I might be explaining this badly, but it's a problem of engineering and size.

A cat can jump from the floor to the dresser, 5 or 6 feet easily and jump back down. That's several times its body length. But an elephant can not jump 100's of feet in the air. In fact an elephant can not jump at all. Even if you scaled up a cat to the size of an elephant it would still not be able to jump to the top of the empire building, because all the materials, muscle, bone tendons don't double in strength when you double the size of the animal. A cat the size of an elephant could not jump at all.

pun not intended.

[Raked aft \\]

"If you built a bigger craft, say double all dimensions, would that not generate higher speed potential??
My logic says it has to. When does the law of diminishing returns kick in??"

If you double the size of the craft you need to make everything four times stronger so it doesn't break in two. Smaller craft have higher top speed but require more wind because they are not as efficient. I think the sailrocket is right in the pocket, it can't get any bigger or it will break.

So make it 4 times stronger, no big deal. I don't know the true numbers, but if you doubled the diameter of a carbon strand rope, you would more than quadruple the strength and just double the weight.

Just looked up amsteel-blue as an example. 1/4" breaking strength 8,600. 1/2" BS 34,000.
This dynamic would apply to all sorts of components on the craft.

if your logic was correct, we wouldn't be seeing 72' winged cats sailing around...

It's not logic its engineering and math. This is why you can make a paper airplane but a glider has to be made out of fiberglass or aluminum. 72' winged cats are right at the edge of our current engineering technology. You can't really make it much bigger with that design.

I might be explaining this badly, but it's a problem of engineering and size.

A cat can jump from the floor to the dresser, 5 or 6 feet easily and jump back down. That's several times its body length. But an elephant can not jump 100's of feet in the air. In fact an elephant can not jump at all. Even if you scaled up a cat to the size of an elephant it would still not be able to jump to the top of the empire building, because all the materials, muscle, bone tendons don't double in strength when you double the size of the animal. A cat the size of an elephant could not jump at all.

pun not intended.

Well if we can engineer a 72' cat, we could engineer a 72' VSR3! The loads would actually be LESS.

As for Elephants & cats your talking apples & oranges

[edt]

Well if we can engineer a 72' cat, we could engineer a 72' VSR3! The loads would actually be LESS.

As for Elephants & cats your talking apples & oranges

Like I said I've done a poor job explaining it. Maybe someone with a better engineering background can make it more clear.

[nroose]

When you double the diameter of a line you do quadruple the strength, but you also quadruple the mass. Doubling the size of a 3 dimensional object generally multiplies the mass by 8.

But if you can make a bigger SailRocket, I will cheer you on!

[edt]

When you double the diameter of a line you do quadruple the strength, but you also quadruple the mass. Doubling the size of a 3 dimensional object generally multiplies the mass by 8.

But if you can make a bigger SailRocket, I will cheer you on!

Exactly. so when you double a three 3 dimensional object in size its mass increases by a factor of 8.

But the strength of all the parts only increases by a factor of 4 because the strength of an object is proportional not to the mass, but to the cross sectional area of all of the parts.

So you double the diameter of your amsteel blue line and its four times stronger.

But the sail rocket itself weighs 8 times more. so when ever you double the size of everything in a 3-d object it is half as strong proportionally so unless you switch to more exotic construction techniques something is gonna break.

This principle applies to hang gliders, airplanes, submarines, cats and elephants, and also the sailrocket.

I am pretty sure that the sailrocket right now is almost perfectly sized.

[c maas]

A good article by Willy Clark:


http://clarksail.com...cket-is-special

[Tom Ray]

I am pretty sure that the sailrocket right now is almost perfectly sized.

How would we know? It's big enough to carry a passenger. Is that necessary?

Would the "perfect" size not be a function of available construction tech? So carbon nano-tubes might mean the perfect size could be larger?

[edt]

So carbon nano-tubes might mean the perfect size could be larger?

That's what I think. We are limited to 2012 technology and can only build so big.

[nroose]

Seems like it's a harder thing to solve. You may end up needing deeper water, and then the wave action may grow by more than the ability of the craft to handle it. And, again, it's not just the ability to build it that size with the required strength, it's also the ability to manage the logistics. An unlimited budget would help, but if it is too hard to get out on the water or takes too long, then you will end up missing any real opportunities to actually go for the record. When the Space Shuttle was envisioned, they said they would launch one each week. Then reality set in, and even with more money than they had thought they would need, it just took too long to turn the crafts around. No matter how good your doctor is, or how much money you have, or what fancy new equipment you develop, it still takes about 9 months for a mother to produce a baby. When you scale up an organization, let's say you need to perform 2x hours of productive work, you also need to manage 2x as many people, which requires more than 2x the managers, because you end up needing to manage the managers. This effect is pretty minor when the organization is small, but when the organization is larger, the effect is larger. And the organization gets harder to change and slower to react to changes in external conditions. The SailRocket team worked on this for a long time, and managed to solve all the logistical and practical and real world problems. If you decide you want to make a bigger one, you would have to go through that again, perhaps with the benefit of lessons learned, but the practical problems of a craft that is 2x longer, 2x wider, 2x taller, and weighs at least 8x (remember you need to beef things up by double to handle the scaling, so that probably adds more weight), will be harder to solve, and you will have a larger organization to solve it. There are many advantages to being small and agile. Perhaps it will work, but perhaps not.

[Raked aft \\]

The 8x increase in mass for doubling 3d objects assumes the object is solid. Most of SR is not, there is a lot of air in the total volume of SR. Certainly the foils, control lines & rods rigging would be solid, but they make up a small percentage of SR's total mass. the wings volume is mostly air as well.

Just look at the progression of the offshore tri's. They scale up just fine, with the current king of the mountain being BP5 which is clearly the biggest of them all.

[nroose]

The 8x increase in mass assumes you double everything, including thickness. In general you would have to more than double the thickness to increase the strength by a factor of 8.

Yes, there are also advantages to scaling up. The advantages for Jules Verne craft have worked out.

The size of the kiteboard gear has not increased, though... You don't see double sized kiteboards, double sized kites, and 2 guys on them going faster...

I think it would be great if you do this, I just was making the point that it is a pretty complex, difficult thing to scale this type of thing up.

[Raked aft \\]

Again I agree on the complexity and cost, hence the reason you won't be seeing me driving a supersized SR anytime soon...

well that is unless I get lucky tomorrow !!

[fastyacht]

If you sit down and do some careful figuring, the size issue will fall out of your work. But it isn't going to come out of thin air pontificating about it:-)

[fastyacht]

My favorite scale trick was that guy in NASCAR in the 60s who was eating everyone on the track. Then one day, one of the other guys looked at the car kinda different, and he went over and started a-measurin'. Of course he figgered it out: the car was only 7/8 ths scale--but the engine was full size :-) That was the beginning of "templates" in stock car racing.

[fastyacht]

The 8x increase in mass for doubling 3d objects assumes the object is solid. Most of SR is not, there is a lot of air in the total volume of SR. Certainly the foils, control lines & rods rigging would be solid, but they make up a small percentage of SR's total mass. the wings volume is mostly air as well.

Just look at the progression of the offshore tri's. They scale up just fine, with the current king of the mountain being BP5 which is clearly the biggest of them all.

Offshore tris have definite advantages to largeness, as they are Froude number limited displacement craft. They are also sensitive to sea state. Larger is faster (except in circumstances where you grow to a resonance with prevailing waves--this was a problem in the North Atlantic with certain warships once upon a time). But the tris aren't *that* long -- yet. Considering that wooden ones were doable at 80 foot waterline and wooden clippers at over 200 feet, with carbon it is clear that we can go a lot bigger. A 300 foot trimaran is not out of the question. Look at that recent enormous carbon monohull ketch -- unlike the disappointing results of Vendredi 13 and Club Mediterranee, these new boats make use of their stability with large sail area--because the structure in carbon can use the power available and they sail up to their Froude numbers.

[JohnMB]

If you sit down and do some careful figuring, the size issue will fall out of your work. But it isn't going to come out of thin air pontificating about it:-)

+1
too may issues to play with to get an easy number,
we don't event know what is limiting the design factor is for most parts of the sailrocket,

It would need careful analysis of lots of parts, some of which will be strength sensitive, some stiffness sensitive, optimization for larger sizes may change the emphasis on some parts, since there will be an interaction between fluid dynamics and stiffness in many components.

I suspect that the engineers best placed to comment on this have already considered it

[yowie]

Is this the first sailboat, ice aside, with seat-belts?

[P Flados]

Structural issues would not be a problem. Aero / hydro would not be a real problem. Scaling it up would be like scaling up an airplane and they get pretty big.

Bigger does mean better physics and it means more wing up in cleaner air flow. Definitely more potential in terms of top speed.

The VSR2 size was pretty much "as big as would fit" in their shipping container. The VSR2 size is also still "not too big" to hand launch and retrieve. They seem to have no problem raising the rig by hand.

They also tow it around with a small RIB.

Larger size means the need for a longer course.

Get much bigger than SR2, and you probably need to design full any direction sailing capacity and you end up operating more like Hydroptere.

Got a six/seven digit sponsor handy?

[ThrillSeeker]

If you sit down and do some careful figuring, the size issue will fall out of your work. But it isn't going to come out of thin air pontificating about it:-)

+1
too may issues to play with to get an easy number,
we don't event know what is limiting the design factor is for most parts of the sailrocket,

It would need careful analysis of lots of parts, some of which will be strength sensitive, some stiffness sensitive, optimization for larger sizes may change the emphasis on some parts, since there will be an interaction between fluid dynamics and stiffness in many components.

I suspect that the engineers best placed to comment on this have already considered it

+1 and +1 again.
There is not a simple scaling relationship for Sailrocket. That is the reason people write their own velocity prediction programs.
Different aspects scale differently. Here are some scaling examples:
Tensile strength of stays scale by their cross section, so strength is linear with weight.
Skin stiffness scales by the cube of the skin thickness, so 2X thicker is 8 times stiffer, and the core is usually less dense than the surfaces.
Drag roughly scales by frontal cross section, so a 2X larger craft would be expected to have 4X larger frontal area for 4X more drag.
Lift roughly scales by sail area, so a 2X larger craft should approximate a 4X larger sail area for 4X more lift.
Lift to drag ratio would therefore be approximately the same for a 2X larger craft.
The cost of traditional yachts about doubles for every 3m increase in water line length.

So, without your VPP program, the answer is not at all evident.

While there may well be a more optimum Sailrocket size, the odds are very small of size making a significant breakthrough in performance. That would be like expecting an oversize biplane to break the sound barrier.

I think the Sailrocket team has exactly the correct approach of using a practical size platform to explore new opportunities for truly breakthrough performance, such as with the complex behavior of cavitating foils.

[shaggybaxter]

If I had remember correctly, and I am interpreting correctly what Paul has written prior, Sailrocket has already more than enough horsepower to go faster, so the focus seemed to be eliminating drag, is it not?
Whilst I do not profess to have anywhere near the intelligence of those involved, if you can somehow magically further reduce drag you don't need to increase the size of anything at all.
Stick SR on a flat water course, or, as the team have mentioned, continue experimenting with foil shape and she'll probably smash records all over again.
SB

[tilmann]

Hey Larso, your sailrocket comes from outer space, being the first sailing vessel not needing any gravity – a milestone in sailing history.

But: Is it pure sailing ?

Below a quote from your blog:

30 June 08:
..."Anyway, we are back... and sure enough, some things have changed in the world of speed sailing since we have been away. The WSSRC (governing body) have added a rule which basically says that the 500m outright record course must be in water over 50 cm deep (my knee joint begins at 50cm high). This effectively eliminates the possibility of wind and kite surfers from getting any benefits from ground effect in one form or another. Now like all rules it can be debated and pushed. Carrying a 50 or even 40 cm fin on a sailboard for speed sailing purposes is not viable... but it might be on another type of craft i.e. ours.
The fact is that there is a performance advantage for some craft when sailing in shallow water as they gain efficiency. We questioned the WSSRC about this some time ago and were advised that they were on the case. We are of the opinion that the outright speed sailing record for waterborne craft should be kept pure. By 'pure' I mean it should simply be the interaction of wind and water on a craft. The proximity of ground (or any other body)and its effect on the dynamics of the craft is known and it is real. To allow certain craft to push this corner of the rule would be to pollute the 'purity' of what this particular record is trying to achieve. Water could simply become a lubricant between the wind and the 'ground' (ground in one form or another). Now I see a lot of moaning on some forums from certain elements of the speed sailing fraternity who currently benefit from shallow water and a lot of their arguements I can sympathise with... but the fact is that the rule needed to get a little more specific. These same parties would be moaning their backsides off if some team of university students wanted to make a point and push the definition of shallow water much harder than they already have by building specific craft and courses to gain maximum advantage from this effect.
It does make it difficult for wind/kite surfers to determine what a viable course is i.e. "How close did you come in to the shore on that last run"? I have watched both disciplines very closely here on the Walvis Bay speed-course and noted the depth that they sail in. Typically, the windsurfers would be OK but the kitesurfers would fall foul (Many of the windsurfers would also on some runs). The fact still remains that they will still be able to sail in much shallower and hence flatter water than we could ever wish for. We draw slightly over 60 cm when planing... and generally are considering ourselves on the edge when we are in less than a meter. As far as finding the best water goes... they still have quite an edge.
I don't know if '50 cm' is the right amount and I'm sure that there will be plenty of debate on the subject. Whatever they all settle on, I personally think that it is a step in the right direction to maintain the aforementioned 'purity' of what a waterborne sailing craft is intended to be..."

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much
Cheers
tilmann

[Cavandish]

Tilman, do you have any idea what "ground effect" in the context provided refers to or how it relates to planing craft?

I'll give you a hint, it has nothing to do with proximity to the shore.

[auscat]

Hey Larso, your sailrocket comes from outer space, being the first sailing vessel not needing any gravity – a milestone in sailing history.

But: Is it pure sailing ?

Below a quote from your blog:

30 June 08:
..."Anyway, we are back... and sure enough, some things have changed in the world of speed sailing since we have been away. The WSSRC (governing body) have added a rule which basically says that the 500m outright record course must be in water over 50 cm deep (my knee joint begins at 50cm high). This effectively eliminates the possibility of wind and kite surfers from getting any benefits from ground effect in one form or another. Now like all rules it can be debated and pushed. Carrying a 50 or even 40 cm fin on a sailboard for speed sailing purposes is not viable... but it might be on another type of craft i.e. ours.
The fact is that there is a performance advantage for some craft when sailing in shallow water as they gain efficiency. We questioned the WSSRC about this some time ago and were advised that they were on the case. We are of the opinion that the outright speed sailing record for waterborne craft should be kept pure. By 'pure' I mean it should simply be the interaction of wind and water on a craft. The proximity of ground (or any other body)and its effect on the dynamics of the craft is known and it is real. To allow certain craft to push this corner of the rule would be to pollute the 'purity' of what this particular record is trying to achieve. Water could simply become a lubricant between the wind and the 'ground' (ground in one form or another). Now I see a lot of moaning on some forums from certain elements of the speed sailing fraternity who currently benefit from shallow water and a lot of their arguements I can sympathise with... but the fact is that the rule needed to get a little more specific. These same parties would be moaning their backsides off if some team of university students wanted to make a point and push the definition of shallow water much harder than they already have by building specific craft and courses to gain maximum advantage from this effect.
It does make it difficult for wind/kite surfers to determine what a viable course is i.e. "How close did you come in to the shore on that last run"? I have watched both disciplines very closely here on the Walvis Bay speed-course and noted the depth that they sail in. Typically, the windsurfers would be OK but the kitesurfers would fall foul (Many of the windsurfers would also on some runs). The fact still remains that they will still be able to sail in much shallower and hence flatter water than we could ever wish for. We draw slightly over 60 cm when planing... and generally are considering ourselves on the edge when we are in less than a meter. As far as finding the best water goes... they still have quite an edge.
I don't know if '50 cm' is the right amount and I'm sure that there will be plenty of debate on the subject. Whatever they all settle on, I personally think that it is a step in the right direction to maintain the aforementioned 'purity' of what a waterborne sailing craft is intended to be..."

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much
Cheers
tilmann

Wah wah wah,at least when Larso stops his vessel it still floats.

[couchsurfer]

Wah wah wah,at least when Larso stops his vessel it still floats.

.........AND there's room for an cooler!!

[Tom Ray]

Is this the first sailboat, ice aside, with seat-belts?

After flipping VSR1, Paul commented that the decision not to have a seat belt had been vindicated, as he was able to quickly exit the inverted boat without drowning.

Does VSR2 have a seat belt?

[cad99uk]

Looks like Paul unclips a seat belt at the end of the 'Magic Mile' video.

[F15 AUS]

I think I read somewhere that the seat belt stops him from going forwards in the event of a crash, but wont stop him getting out in the event of a backflip

[larso]

Hi Anarchists... well here's that thing you've been waiting for. And the blog about it is up too. I hope the wait was worth it.
Blown Away. Vestas Sailrocket 2 at 65+
Enjoy.

[Tom Ray]

How was the overhead video taken?

And can't you hold your head a bit more still at that speed? At least you remembered the helmet cam!

[Rasputin22]

Congrats guys!

70 is within reach. Watching the video, I was wondering about the kiter in chase and it is obvious how as you bear away Vestas just smokes him. Then at the end of the clip, I realized that the purpose of the kite is for the aerial footage from a GoPro suspended from the kite! Am I correct in this assumption? If so, that is almost equally brilliant.

[Innocent Bystander]

Massively intense. Congrats again.

[Tucky]

The overhead shots are fantastic at showing the energy and balance. Wonderful.

[Guitar]

Don't normally need to wipe a tear from my eyes when watching a sail BOAT. Can't imagine you and the teams' elation right now.

Well done, again, and smoke the 70 barrier!

Should rename the technique as "Slingblading". She certainly looks like a sling blade from the air.

[Goonda]

How was the overhead video taken?

And can't you hold your head a bit more still at that speed? At least you remembered the helmet cam!

From Paul's blog:
http://www.sailrocket.com/sites/default/files/11_1200x800.jpg
"BERNT WITH HIS GOPRO PLANE. THE FOOTAGE IS AMAZING. THIS GUY HAS SKILLS. BLOODY WELL DONE IN 30 KNOTS OF WIND."
http://www.sailrocket.com/node/663

[familysailor]

How was the overhead video taken?

And can't you hold your head a bit more still at that speed? At least you remembered the helmet cam!

Amazing!
He does look a little like a "Beatle Bopping Head Doll" Does he not?

Talk about your extreme thrill ride....

[JohnMB]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

[Mainah]

The speed sailing "commission" has rules governing minimum depth. Tilmann should know a thing or two about minimum depth.. given the bay he always sails / films... with the occasional "bare" spot They have been doing this in the "french-trench" for years anyway.. which leads me to wonder why we have have not seen Tilmann there yet? Hmm? You've got the experience.

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

[couchsurfer]

........and a call goes out among the world,,,,,,, ........''that's gotta be it,,,,,that's gotta be it''


 wind in face.jpg   9.79K   0 downloads  wind in face3.jpg   8.62K   3 downloads  wind in face 2.jpg   23.17K   2 downloads  wind in face 4.jpg   9.83K   2 downloads  wind in face 5.jpg   6.1K   1 downloads

....2020AD....a spin off from the sailrocket project was an international chain of 'windstudio's,,where people could record their voices while facing 70knot winds!

...........''that's it!!!,,,,,,,that's IT!!!!''

Attached Files

•  wind in face 6.jpg   54.73K   0 downloads

[MR.CLEAN]

Hi Anarchists... well here's that thing you've been waiting for. And the blog about it is up too. I hope the wait was worth it.
Blown Away. Vestas Sailrocket 2 at 65+
Enjoy.

The fucking acceleration at the spot where I've started the video is absolutely surreal.

http://youtu.be/pipGWQmerEQ?t=52s

[couchsurfer]

..........ten years of buildup to 'the' day........=$_,____,000

........that little chuckle as you slow at the end of the record run...........=priceless!

[Willy Clark]

A little more from Larso for those who are interested - http://clarksail.com...-his-own-words/

[muckypuffin]

Thats the greatest thing I've ever seen. The run itself, the fricking spaceship sail rocket, Malcolm and his sums, filming it with an RC plane and nonchalantly writing the new outright sailing record on the side of a shipping container with a sharpie. Jesus Christ!

I'm fucking blown away, congratulations to the team and never underestimate Malcolm and his numbers!

[P_Wop]

Paul and Helena and Malcolm and team.... Just wonderful - huge kudos to y'all!

[HASYB]

Every once a while something really magical happens and I recognize a cosmic orgasm when I see one.
You Paul, Helena and team started dealing in them and came to full maturity in the last run.
My goodness what a trip; the honesty, intensity, exitement, the plot, the poetic like reporting with the video's, music, style.......... The shear joy & celebrations. Everything oozes quality & refinement.
I realize now this had to be; the record was yours from the beginning.
And again; the way you shared this adventure deserves the greatest possible respect.

Moved to ears in my eyes some times, glad you guys go home now.

Cheers again to the lot.

Hielan

[Doug Lord]

Tremendous accomplishment, Paul and Team! Congratulations! Was the aerial footage from the rc plane with a go pro camera?

[Goose84]

Clean is spot on, that moment when he locks in, and I think make a quick turn down the track, the boat just fucking takes off. Awesome stuff.

[auscat]

That is totally insane! Definatly worth waiting for.Onya Larso.

[furr_ball]

Congratulations from Oz.

Just awesome.

Can't believe no one has asked........What's it rate........

[Tom Ray]

How was the overhead video taken?

And can't you hold your head a bit more still at that speed? At least you remembered the helmet cam!

From Paul's blog:


"BERNT WITH HIS GOPRO PLANE. THE FOOTAGE IS AMAZING. THIS GUY HAS SKILLS. BLOODY WELL DONE IN 30 KNOTS OF WIND."
http://www.sailrocket.com/node/663

Cool, thanks for that. I was also wondering if somehow the kite was filming, but the camera appeared to track the boat, which made me think it must be something else. An RC GoPro plane is indeed something else.

[BIAM]

very, very, very, impressive

[BalticBandit]

What I find amazing in the frontPage video is how at 53/54 seconds in... the boat is already flying and he bears off and sheets in, and it acelerates like someone set off a rocket in its butt.

[RParentsail]

Almost too fast!

[Hemi]

Clean is spot on, that moment when he locks in, and I think make a quick turn down the track, the boat just fucking takes off. Awesome stuff.

I love that moment too - imagine the g force pushing Paul back in his seat!

[Foolish]

What an incredible feat.

This boat will see the other side of 70 oneday.

When I look at the small bow foil digging into the water at an angle, all I can think of is ways to reduce resistence further. I think there is 5 knots waiting to be discovered right there for the engineer who can eliminate the resistence and still steer the boat.

[tilmann]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

[tilmann]

forgot to say: Such a ventilated foil with extremely low aspect has a lot of drag of course ...

[yowie]

What an incredible feat.

This boat will see the other side of 70 oneday.

When I look at the small bow foil digging into the water at an angle, all I can think of is ways to reduce resistence further. I think there is 5 knots waiting to be discovered right there for the engineer who can eliminate the resistence and still steer the boat.

You realize that the front points into the wind and the foils point more or less in the direction of travel?

[moody frog]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

Yes a kiteboard is not a windsurfer, but technically a fast (speed) board is a foil in itself, (at least is it what shapers are looking for: a foil the area which decreases when speed increases). At speed they tend to sail on the one-foot-off surface or part of it (the rest is up in the air) and the fin is just a winglet to that foiling surface.

Attached Files

•  speed_Page_1.jpg   32.51K   16 downloads

[ThrillSeeker]

Paul,
Thanks so much for sharing the excitement with us! Spectacular achievement! Thrilling video; Beautiful photography; Inspirational team reactions; Brilliant technology; Elegant execution. Your whole team provides an excellent role model for the sailing community.
I hope your team’s skills are leveraged for even greater adventures – you deserve that.
It seems there are some America’s cup teams that could use some foiling technology breakthroughs. Who will be the sponsor for Sailrocket 3?

• Artemis
• ETNZ
• Luna Rossa
• Oracle
• Vestas

Best of luck in extracting the cash out of your achievements.

[duncan (the other one)]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

well.. except for the guy who goes out on a wet icy lake in a hurricane and gets blown downwind.

[shaggybaxter]

Man, I just keep playing that video over and over, I can't get enough of this.
Words don't do justice to what you lot have achieved, so a heartfelt thank you to all involved.
This couldn't of happened to a nicer bloke, congrats to Larso, Vestas and the entire VSR2 team, you've earn't your place in history.
I hope you don't go out again, I'm rapidly becoming a raging alcoholic trying to keep up with these celebratory tipples...
SB

[Cyrille Hydrogene]

Clean is spot on, that moment when he locks in, and I think make a quick turn down the track, the boat just fucking takes off. Awesome stuff.

The acceleration is unlike anything I've seen on the water. Unbelievable!
Maybe Larso can send us the Trimble file, so that we can compute the number of Gs during the acceleration.

The orange color of VSR2 is a great hommage to the Bell X1 and the first man over Mach 1. In many ways, Paul Larsen reminds me of Chuck Yeager. He really has the Right Stuff.

[usa 917]

Unreal.. Congratulations

[Ryley]

Congratulations from Oz.

Just awesome.

Can't believe no one has asked........What's it rate........

-200 point to point and 267 around the buoys.

[couchsurfer]

Words don't do justice to what you lot have achieved, so a heartfelt thank you to all involved.

SB

,,,,yeh,,but that sigh at the end of the run is worth -everything-!!!

[JohnMB]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

Well I suggest you do some investigative work on this an demonstrate that in 5cm of water a kiteboard is acting in the same way as in terms of fluids and ground interaction as in is in 50cm of water, I'm sure if you do so, the WSSRC will reconsider the rules. Some simple tank tests should be sufficient to do this, or at least challenge the current state of knowledge on this.

Personally I doubt that a kiteboard in 5cm of water is not being substantially affected by ground effects, especially of that 5cm is over a fine silt, (like burnham on sea for example). I know that boards are riden on the edge, but that still leaves a substantial wetted area of board, as the effective beam, I would be surprised if you could generate enough lateral resistance without the effective beam of the board being greater that 10cm so we would still be in the regime of the depth less that 1/2 the beam.

As noted no-one has suggested that the purity of the record is affected by waveheight, and the rules were not altered because of concerns about waveheight, the rules where set because of concerns that the physics of vessel-water interaction where very different at very shallow depths (like 5cm).

[Barkley]

Onya Larso. Absolutely EPIC run.

And thank you for being a completely open book about the whole process. Anyone who follows along really feels part of the experience..

[tackoften]

Paul can u please get the doco up an running as soon as,,,you'll make a packet for the team and we will have something to share with our friends around the barby,,thanx

[Reht]

Hi Anarchists... well here's that thing you've been waiting for. And the blog about it is up too. I hope the wait was worth it.
Blown Away. Vestas Sailrocket 2 at 65+
Enjoy.

The fucking acceleration at the spot where I've started the video is absolutely surreal.

http://youtu.be/pipGWQmerEQ?t=52s

And I thought that turning the corner in a skiff was scary acceleration. What I wouldn't give to know exactly what larso was thinking the first time he felt that acceleration...

Man, you guys just keep delivering! That is one heck of a video.

[tilmann]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

As noted no-one has suggested that the purity of the record is affected by waveheight, and the rules were not altered because of concerns about waveheight, the rules where set because of concerns that the physics of vessel-water interaction where very different at very shallow depths (like 5cm).

So if "purity" doesn´t matter: Why ban the ground effect (if it exists) ?
What I mean is: Each sailing vessel has its own advantages and disadvantages. A kiteboard for example can run in shallow water which means no waves and maybe (nobody knows) a little ground effect. On the other hand - being a ventilated foil with extremely low aspect - a kiteboard has a huge amount of drag which has for sure way more effect than than the little (presumed) drag reduction caused by ground effect.

[Beau.Vrolyk]

What an incredible feat.

This boat will see the other side of 70 oneday.

When I look at the small bow foil digging into the water at an angle, all I can think of is ways to reduce resistence further. I think there is 5 knots waiting to be discovered right there for the engineer who can eliminate the resistence and still steer the boat.

You realize that the front points into the wind and the foils point more or less in the direction of travel?

Foolish, have a look at the video. You can see the apparent wind angle by looking at the little wind point mounted just ahead of the helmsman atop the hull. It shows up a number of times in the film. The hull (sausage) is actually receiving the wind from just slightly off the starboard bow even though the direction of travel is about 5 or 8 degrees off the port bow at full chat.

[tilmann]

forgot to say: it´s again selflimiting - if a foil cannot sink deep enough into the water it cannot generate sufficient lift. And less lift means less speed.

[OZCAT]

Notice the only person criticising is into 'speed kiting'. So tilmann, when are you going to take up real sailing?

[Guitar]

I would think now would be a good time for the kiters to get their own designation as some other craft, not touching this speed, EVER!

.

No interviewer as asked Paul yet, when will you try for 70?

[Alpha FB]

I remember when I saw the first pictures of sailrocket, a few years back, thinking

Weird...
Ugly..
Not a real boat..
How can that possibly work…

Since then, I’ve followed the team, read the accounts on the continuous development, on the hurdles that needed to be overcome, the boat being honed to a fine edge for a single purpose…

And once I understood that, I was converted!

Now I think she’s an absolutely beautiful machine, designed perfectly for her job, which she performs efficiently, elegantly, powerfully…

I’m really looking forward to seeing her exploits continue next year!

[JohnMB]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

As noted no-one has suggested that the purity of the record is affected by waveheight, and the rules were not altered because of concerns about waveheight, the rules where set because of concerns that the physics of vessel-water interaction where very different at very shallow depths (like 5cm).

So if "purity" doesn´t matter: Why ban the ground effect (if it exists) ?
What I mean is: Each sailing vessel has its own advantages and disadvantages. A kiteboard for example can run in shallow water which means no waves and maybe (nobody knows) a little ground effect. On the other hand - being a ventilated foil with extremely low aspect - a kiteboard has a huge amount of drag which has for sure way more effect than than the little (presumed) drag reduction caused by ground effect.

I didn't say purity doesn't matter

I said that wave height has nothing to do with purity as expressed by paul in the post you where criticizing.

[fastyacht]

End of quote.

So where is the purity in your run, Larso ? During your run you used more than only wind and water to go fast. By running alongside the shore as close as possible. In order to have waves as small as possible. So the proximity of the shore had a clear effect on your record.

Apart from that I like you very much :)/>
Cheers
tilmann

I don't think anyone has ever considered in 'unpure' to try to eliminate waves. (by sailing close to the shore)
the 'impurity' referred to is the huge reduction in drag which occurs when a planing surface is working at a depth of less that 50cm.

If you allow any depth, then the logical extension is to just use an iceyacht, since while moving they 'float' on a thin film of water, so that counts.... right?
In fact lets propose that, if the WSSR ever remove the depth restriction just adapt the sailrocket design to work on ice and add sensors to detect the water film level under the blades.

For kiters the ground is what the shore is for Sailrocket: It reduces wave height.

It´s true that there are several investigations which found out that flat bottoms have less drag in shallow water. But in all these investigations they "ride" the board flat. Kiters however ride their boards on the edge
A kiteboard is not a windsurfboard - kiteboarders use their board as a foil. A kiteboard is a kind of ventilated foil with extremely low aspect. Like any other foil it needs a minimum water depth to generate sufficient lift (ca. 5 cm) On 1 cm (using water only as a lubricant) you just slide around without any control. So it´s selflimiting - a rule is superfluous.

So don´t worry - after the removal of the depth rule speedkiters would stay what they are: just vessels on water driven by wind.

Well I suggest you do some investigative work on this an demonstrate that in 5cm of water a kiteboard is acting in the same way as in terms of fluids and ground interaction as in is in 50cm of water, I'm sure if you do so, the WSSRC will reconsider the rules. Some simple tank tests should be sufficient to do this, or at least challenge the current state of knowledge on this.

Personally I doubt that a kiteboard in 5cm of water is not being substantially affected by ground effects, especially of that 5cm is over a fine silt, (like burnham on sea for example). I know that boards are riden on the edge, but that still leaves a substantial wetted area of board, as the effective beam, I would be surprised if you could generate enough lateral resistance without the effective beam of the board being greater that 10cm so we would still be in the regime of the depth less that 1/2 the beam.

As noted no-one has suggested that the purity of the record is affected by waveheight, and the rules were not altered because of concerns about waveheight, the rules where set because of concerns that the physics of vessel-water interaction where very different at very shallow depths (like 5cm).

A kiteboard operating in very shallow water, where the edge of the board is very close to the bottom, will benefit from the "end plate" effect of the bottom--inhibiting the tip vortex and increasing the effective aspect ratio of the board (which is actually a foil, as I pointed out some time earlier). Because the board is very inefficient--due to ventilation and low aspect ratio--the effect of constricting the tip vortex can be expected to be significant. In fact I posit this effect is of far greater importance than the improved planing effect of shallow water.

[couchsurfer]

Notice the only person criticising is into 'speed kiting'. So tilmann, when are you going to take up real sailing?

........Oz,,if yer don't think kiting is real sailing,,you should just crawl back in your egg

...it's pretty easy to see that kiting is the purest form going!.............if you open your eyes

[mad]

Just agree to differ guys, we really don't need another pissing match about this. Thanks

[couchsurfer]

Just agree to differ guys, we really don't need another pissing match about this. Thanks

...taking exception to a comment does not a pissing match make!