"It is my assumption, that a rapidly shoaling wave, virtually one that is about to break is a somewhat different beast than that of a deep water wave "
… Points out an important issue that is continually missed when discussions around this subject surface.
Those who rarely ride steep, hollow breaking waves could easily miss this important point. (and apparently many do, miss it that is) There is no question that much of the water in a breaking wave is moving forward with great force toward the beach and that anything immersed in that water or that is hit by that water will get the positive or negative effects of that movement as the case may be.
Bill we are all aware that a pitching lip contains water which is moving towards the beach, and we haven’t ‘continually missed’ this fact at all. . . we have been discussing the physics of surfing on the wave face. . . if you look back at previous discussions there are plenty of references to the fact that riding a pitching lip is a different case from riding the wave face.
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A surfboard’s interaction with the breaking wave is not governed solely by Dalrymple’s example and in fact most contemporary wave riding in breaking waves has little to do with it. .
Not solely, but mostly
Even contemporary surfing is conducted mainly on the face of the wave not on the breaking lip. . . when tuberiding for example the rider is using the sloping face of the wave not the breaking lip, it’s only during floaters and the like that the forward motion of breaking lip is used, and that is a small percentage of the time. . . riding ‘in breaking waves’ still requires that the wave face is ridden most of the time.
Is it possible that your perceptions of which part of the wave is the lip and which part is the wave face, is too limited? I think if you broaden your perception you will find that once the wave begins breaking or shoaling or whatever you want to call it. The original wave form becomes grossly distorted. Once that takes place the model of the circling water barely applies. There are remnants of it there, of course but most of the what you would call the wave face, is really forming into the lip. That’s way I mentioned in my post that I think there is confusion regarding what to call and how to measure this transitional area. The forces at a surfers disposal, in a powerful tubing wave, ridden close to the curl, is very different then the the power model you commonly promote. Slow, flat, mushy waves are a whole different issue and while that is fairly common in most peoples back yards it isn’t where I live and play.
Duke and the boys in rolly Waikiki waves in the early 1900s vs the contemporary surfing of the North Shore today aren’t tapping the same forces in the same way. The power in contemporary surfing is at least 50% derived from time spent on surfaces of the wave that few considered even consistently ridable 30 years ago. That is the lip, or in the old school surfing view, the upper 30% of the wave or so.
At Pipeline, it doesn’t matter a hoot how the molecules of water are cycling in the remnants of the original wave form. By the time the wave is catchable, it is a split second away from it being 75% Lip, and 25% dying wave form. A huge amount of energy is being imparted to the surfer from the forward thrust of the wave (lip). So much so that, that is what makes it such are hard wave to ride as are many steep, hollow waves. When the same kind of wave is smaller it is less noticeable but the same issues apply.
I understand your theory Roy, about where you feel that the power comes from but you tend to under rate this force that I am talking about. Causing me to speak up on its behalf. Maybe I have missed your comments otherwise, if so I apologize. I know you understand what I am talking about. Can you find a way to fit it more fairly into your model?
It appears to me that this thread and the Wing Nut thread are skirting the “dynamics” issue of surfing. The both take snap shots of very dynamic models and make assumptions about their performance across a broad range of variables. Angle of attack and flow rate are two huge variables about how efficient a foil moves through a fluid medium. In the Wing Nut thread there is a precieved deficiancy about flats on fin foils. Well, at higher angles of attack and higher flow rates there are inefficiencies or limits that can be improved upon by a curved foil. But, those gains can be at the expense of lower flow rate performance.
Everything in life is a compromise. If your just going to cruise at San Onofre, Termaline, Cowls or Queen’s are you really going to to feel a difference? Is that difference worth the extra expense? Where as if your constantly pushing the limits in extreme conditions can you afford the compromise of not optimizing for those conditions. If you’re trying to pump up enough speed at you local beach break to float over the next section or pump back out of the soup, flat or concave inside surfaces are a benifit. Where as, in high flow rate scenarios where say your running for for life to beat the lip at Jaws, Maverick’s or Todos then I’d sure wouldn’t want to be dragging the extra turbulence around that a flat or concave inside surface would generate.
There are those that can and will pay to have the best tools for each and every situation. And, there are others that just want to have fun and don’t want to spend a large amount on something they may rarely if ever precieve a benifit from. So, to meet the needs of as many customers as possible, manufacturers provide choices. It’s up to the customer to decide what’s important to them. If the customer doesn’t want what you’re making you either change or die. And, competition will insure that there are always options.
The flow models really should be vector arrays integrated across a range of flow rate and angle of attack and expressed in a graphical model. Then you can visualize where the efficiencies occur and ineffiencies occur. Marketing will often take a simple snap shot model at zero degrees angle of attack and optimal flow rate to maintain laminar flow and say see how bitchin our product is. But, just remember everything is a compromise and you need to decide what are the important variables for you.
Is it possible that your perceptions of which part of the wave is the lip and which part is the wave face, is too limited? I think if you broaden your perception you will find that once the wave begins breaking or shoaling or whatever you want to call it. The original wave form becomes grossly distorted. Once that takes place the model of the circling water barely applies. There are remnants of it there, of course but most of the what you would call the wave face, is really forming into the lip. That’s way I mentioned in my post that I think there is confusion regarding what to call and how to measure this transitional area. The forces at a surfers disposal, in a powerful tubing wave, ridden close to the curl, is very different then the the power model you commonly promote. Slow, flat, mushy waves are a whole different issue and while that is fairly common in most peoples back yards it isn’t where I live and play.
Bill, there are plenty of hollow waves outside Hawaii and yes I have ridden hollow waves… . . . but I’m not buying into the notion that ridng the face of a hollow wave is any different from riding any other kind of wave face.
The face of a wave is the part which is below vertical, and in the tube that’s where the surfer is riding, the forces being used are the same as those being used on any other non tubular wave face. . . . . . they are not ‘very different’. . . only the view is different !
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At Pipeline, it doesn’t matter a hoot how the molecules of water are cycling in the remnants of the original wave form. By the time the wave is catchable, it is a split second away from it being 75% Lip, and 25% dying wave form. A huge amount of energy is being imparted to the surfer from the forward thrust of the wave (lip). So much so that, that is what makes it such a hard wave to ride as are many steep, hollow waves. When the same kind of wave is smaller it is less noticeable but the same issues apply.
When riding in the tube at pipeline the surfer is riding the face of the wave, and the physics involved are the same as with any other wave face.
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I understand your theory Roy, about where you feel that the power comes from but you tend to under rate this force that I am talking about. Causing me to speak up on its behalf. Maybe I have missed your comments otherwise, if so I apologize. I know you understand what I am talking about. Can you find a way to fit it more fairly into your model?
Firstly, it’s not ‘my’ theory. . . . and it isn’t based on a mere feeling. . . . the fact is that when the face of the wave is being ridden most of the power driving the surfer comes from the power of the wave lifting the board and rider up, and imparting gravitational potential energy to the rider.
What you are doing is talking about riding in or on the throwing lip, which is a different case, as has been mentioned many times. . . …
so yes you have missed the fact that it has been mentioned, but we haven’t discussed it much except to say that it exists.
As you know, people love to mystify surfing, hollow waves, and Hawaii. . . . so if you are looking for popular support you are going the right way about it by implying that we have on one hand a dry theory concocted by Tom Bloke, mush rider, who hasn’t been to Hawaii and has never been tubed. . . . and on the other hand we have a theory from Bill Barnfield, Hawaiian legend, who builds boards for pipeline. Most people in my experience will decide on the basis of who is talking rather than what is said, so it’s a smart move on your part… . . . . . nevertheless none of the emotive content can change the physical facts.
The face of Pipe is the same as any other wave face??? REALLY??? I now know one Swaylocker who has never seen Pipe in person.
Roy, after you take us up on the J-Bay challenge (remember that–when Roy wrote that he could out-surf Curren at J-Bay?), why not paddle out at Pipe? Once again, here’s my offer–you get barreled at Pipe on a good day and I’ll pitch in for the plane tix.
On the other hand, could the basic ideas being discussed here be somewhat correct (gravity, water pushing on the baord, etc.)–but the assertion that Pipe’s face is the same as any other waves’ be somewhat ridiculous? At the very least, the angle, placement of the rider, amount of water, speed of moving water, and overall force be quite different than most waves??? Could those differences have any real-world impact?
There is no need to mystify hollow waves, Hawaii, and/or Pipe. There is a legitimate need to recognize the obvious differences in actual measurable variables (angle, size, quantity of water, speed, etc.) between hollow waves, Hawaii, Pipe and most other places in the world.
Here’s a prediction–Roy responds by changing the subject…and in a month claims that not only can he outsurf Curren at JBay AND has mastered Pipe’s hydrodynamics without ever even seeing it, BUT he can ALSO out-walk Jesus on water! The simple principles involved are quite elementary, see…
Fact is, what I’ve presented is at best, equivalent to a sketch, and probably a sketch by someone without thumbs, using a really big crayon, on a very small piece of tissue paper, and who is obviously myopic; it is by any account crude, oversimplified, riddled with errors in reasoning and possibly verging on useless.
But who can resist ‘looking’ under a surfboard? Okay, well maybe a lot can - but I just have to try and take a peek.
I’m also hunting for general principles. And though I completely understand the value of experience in such a ‘hunt’, a part of what I seem to be likes to hunt in other ways too.
Futile? Possibly. But, just for the record – experience is king – nothing presented in this or any of my other threads (of and for the bewildered?) trumps experience.
Trucker, the physical principles governing a pipeline wave face are the same as any other wave. . . .
You are correct that the amount of force involved varies between waves, but the physical principles are the same.
much of your post is of a personal and baiting nature so I am ignoring that, as I don’t want the thread hijacked in my name, however just for the record, the common idea that I have said that I surf as well as Tom Curren is a myth, I didn’t ever say anything of the sort. . . . and I don’t now. … . I have no comment on who is ‘better’ at surfing than anyone else, it’s just meaningless jabber as far as I am concerned and has nothing to do with the subject matter.
here’s a place where you travel much faster and farther across the wave than you do towards the shore.
they don’t understand the term cutback/foam bounce here and are travel much faster than Mr. Curren at j-bay… probably because of how high that water is bouncing off the reef…
Also if you watch the first video very closely you’ll notice that at these speeds only the back 2-3 of everyone’s board is actually making any contact with the water.
Also what’s the benefit of all this theorizing about hydrodynamic water flow propulsion in relation to the current form of surfing with seems to be all the rage with the young folks nowadays. Seems like they are more interested in being out of the water/wave than interacting with it…
Getting vertical and launching is more fun to the new generation than how far down the line or how long the ride is anymore… So is this just another discussion of a solution to a nonexistant problem.
Seems like we should be asking…
how do you surf and control a board in the air versus on the water and still be in control to keep it smooth and flowing.
old school air
new school air
cruise and pose
haul ass to not eat it
or boost and try not to eat it
here’s a perfect example of how its all coming togethor…
It appears from that you understood my comments about contemporary surfing being 50% of the time in the Lip area. Thanks for helping clarify that with the great shots and the damaged goods video http://surfermag.com/…damaged-goods-parko/ The surfing there was exactly what I was talking about. Many of the cutbacks were 180 degree direction changes that never even left the upper 30% of the wave.
Mr Casey, from a dumb arse pov can I just try and clarify what you and Roy and Bill are talking about and maybe throw in my 2c from experience.
Are you saying that there is an upward flow of water as a wave breaks and according to how rapidly and forcefully this occurs (extreme example Pipeline or Chopes) this will flow across a board from rail to rail (that is compared to nose to tail) and could be a major propulsive force for a surfboard on a wave ?
Roy are you saying this upward flow does not occur or that it occurs but is not a major component in terms of propelling a surfboard ?
From my experience the upward flow of water in a rapidly shoaling big wave is very evident and one of the major factors which must be considered in terms of surfboard design. Anyone who has tried to paddle into a wave at Waimea or Pipe knows firsthand that the upward flow of water as the wave rapidly drags on the bottom and is forced upwards is extreme. It is the upwards flow of water which must be paddled against (you are virtually paddling downhill while the water drags you upwards.)
The upwards flow of water is also very evident at the base of the wave and leads to a sort of flowrider effect on hollow waves. Greenough refers to this effect as “bottom tension” and designed all his craft for hollow waves around this phenomenon. I can’t put this into an equation but it seems pretty obvious from empirical observation that there is an upward flow that it is increased in hollow surf and that it effects the bottom of a surfboard. Steve
So because some people ride the lip occasionally or jump into the air, that means that we shouldn’t discuss surfboard dynamics on the wave face ?
Surely if you don’t want to discuss surfboard dynamics on the wave face then you should just leave the thread alone for those who do !
Oh, and by the way without surfing on the wave face it would be impossible to get air anyway, so it is relevant. . . surfboard dynamics on the wave face isn’t just about going fast down the line it applies to all surfing.
Lennox I am saying that upwards flow provides 95% or more of the power available to board and rider when riding the wave face, and that the rest is due to muscular input frrom the rider.
Quite clearly some waves lift faster than others, and some parts of a wave lift more strongly than others, however that doesn’t change the fact that the same process occurs at 10 foot pipeline or at a 2 foot beachbreak.
Riding on the part of the wave which is beyond vertical and is pitching forwards is different, however that’s not what is happening when riding inside the tube, at pipeline or anywhere else.
Sorry Roy , I thought you were saying upward flow was only important in that it lifted a surfboard rider and allowed gravity to take effect not as a propulsive effect in and of itself. steve
It appears from that you understood my comments about contemporary surfing being 50% of the time in the Lip area. Thanks for helping clarify that with the great shots and the damaged goods video http://surfermag.com/…damaged-goods-parko/ The surfing there was exactly what I was talking about. Many of the cutbacks were 180 degree direction changes that never even left the upper 30% of the wave.
Bill I just checked that video clip and at least 95% of the time the rider was riding the wave face. . . you seem to have decided that if the rider is in the top 30% of the wave then he isn’t riding the face ( that is the argument which you used previously) . . . . but that isn’t true. . . it’s clear that the rider in the clip is riding the wave face ( which we have defined as the portion of the wave which is below vertical) most of the time.
If you doubt this then please look again, any time that the rider is below the lip,has his centre of gravity above the board, and has the bottom or rail in the water then he is riding on the wave face and the usual physical laws apply. … . … this is the case during the cutbacks which you mention. . .
Sorry Roy , I thought you were saying upward flow was only important in that it lifted a surfboard rider and allowed gravity to take effect not as a propulsive effect in and of itself. steve
It’s REpulsive, as everybody says when they talk about paddling against it.
You point is well taken. So, how close, or whether they are close at all, is the issue - for the moment, at least.
It seems reasonable that any analysis should include the case when the difference between the two forward components of velocity is not small. This is especially true given that I do not have any real numbers to argue otherwise at this point. What we would call propagation speed of the curl region is not a quantity that appears too often in the literature - estimation is required.
Anyway for me its simple. I figure what a person does with their kinetic ‘coin’ (energy) is their business. At the moment, I’m interested in how they accumulate that treasure.
And remember, you can’t have smart arses without… dumb arses?..which hopefully means something other than which side of that equation I’m likely to found on.
