(Anyway, was the fact that a wave moves forward supposed to justify flat bottoms somehow?) (Concave bottom if carried to the rail allows more penetration and lift and focuses lift toward the rider’s heels or toes, a good thing if you want to exploit it)
Uuumm… There’s a lot of trains of thought on this. One is that big, wide single concaves allow more rocker. There are other trains of thought.
The real question is, are you really a good enough surfer to feel the difference? If so who is your sponsor
Silly, everyone else,
most people just need a thicker/wider board
I think this is the real point to what Silly is trying to say. A lot of surfers are so focussed on their image and what the pros do that they buy into any gimmick that’ll make them “more like the pros”. To the detriment of their own surfing. Most people simply need a bit more volume… Personally I agree with that.
I see more references to air-foils. Just wanna make sure people keep something in mind… Yes, there are similarities. And there are differences. Air foils go through air only. Surfcraft skim a surface skin (on a non-compressible gas).
Just wanna make sure noone ignores either side - balance.
IRT upflow.
Upflow on a typical wave is in the order of 1-2m/s (3.6-7.2km/h aka 2.237-4.474mph). As you may remember I think that isn’t sufficient for it to be a critical factor… But it is a part of the wave energy and plays some role. On a longboard trimming across a wave and climbing it plays a bigger part than on a short, narrow shortboard carving.
KCasey - to make a lot of progress in thius discussion I think you are going to have to openly acknowledge the importance of other factors. Most specifically buoyancy, gravity and the impacts of design. I don’t see anyone buying upflow as the most important factor on it’s own.
so we are all agreed its not a gravity sport!
Yes and no. Gravity helps us harness wave energy. Sure, there are other energy sources but they aren’t significant compared to wave energy. Other sources also need gravity to function - e.g., that pumping isn’t possible without gravity… Gravity needs to be there for things to work. To me it’s an energy sport
I don’t see anyone buying upflow as the most important factor on it’s own.
But upflow is what creates gravitational potential energy. . . because upflow works against gravity at all times it is able to do a lot more work than horizontal flow… .
Doug, I’m interested to know 1) where you got that range of upwave flow speeds,
and 2) what that indicates–like if that’s what’s left after you subtract the forward waveform velocity or if it’s just flow speed toward the crest on the face,
er…
like if you could just hung out on the nose, straightoff, on the crest, that’s the velocity coming up the wave at you?
If you subtract the overall wave’s beachward V would you get another lower figure?
But aside from that, 3 or 4 miles an hour doesn’t seem like a very influential flowspeed any way you slice it. Unless you add, oh, say, GRAVITY and grade, and forward wave V.
Frankly I’ve experienced tons of waves with forward speeds in that range and you can’t do much of anything with that
Man, fuck this. Go to the beach, grab a stick, float it, paddle a few yards away and watch it. That alleged flow doesn’t net out to shit. Fucking guy sees a plank stuck on a wave in a 35 y.o. diagram, thinks he sees a trimming surfboard— microthinking bullshit…
But seriously. Wave speed and wave hight tell you how quickly a wave passes a stationary point. That’s usually under a second from trough to peak. Say 1/2-1sec. Wave height varies and so does speed. But the ballpark is still going to be in that range. Wrong? Right? Why?
That’s why I say the upflow force isn’t in the same ballpark as a stationary wave.
And yep, gravity is the big key. I think when you aren’t planing buoyancy lifts you to the peak. I reckon upflow plays a part, but I don’t think it’s the biggest factor. Guess I finished chewing on that
Sure, once you are planing you can use upflow to climb the wave face.
Buoyancy is simply the interface between gravity and the flow up the face of the wave. . . . the upflow is what lifts a surfboard, planing or not. . . . how else can a wave lift anything, except with upflow ?? Upflow is the only way that a wave can lift anything !
I reckon upflow is just part of the way the energy band manipulates the water particles, sucking in water from the front of the wave to make the waves rise (and peak). So upflow is a result of the energy band.
But upflow doesn’t actually “push” the board up the face that much, because the upflow isn’t strong enough to do that (at least in most cases).
If you could pull out a magic wand and freeze a wave so that the particles weren’t moving and the wave wasn’t moving - then paddle towards the wave you will still go up. Buoyany vs upflow. Without buoyancy we’d sink to the bottom and the wave wouldn’t have a lot of effect.
It’s like the difference between gravity powering a surfboard directly and it allowing us to harness the wave energy. Subtle but important differences.
But if you are floating in the water, the water can’t lift you up further unless it moves, or flows, upwards. . … the water has to get up there somehow. . . it can’t do it without flowing. . . and when you are sitting in the water being lifted by a wave you are quite simply moving up along with the water flow, surely that’s obvious?. … … buoyancy can only lift you to a fixed point relative to the water surface. . . . if you are going to lift higher the water has to lift. . . another word for flow.
It was fine when you first brought up your theory, but when you ignore facts that go against your theory, you end up looking like a crazy person. It seems like at this point you just don’t want to admit you are wrong. It’s okay to be wrong.
Here are the facts that we should be concerned with:
2.) The only water particles that matter to surfing are on the surface.
3.) A water molecule on the surface essentially stays on the surface.
4.) There is a difference between the wave and the water molecules.
5.) The wave has energy.
6.) The wave lifts the water molecules.
7.) The water molecules have no energy of there own.
8.) The wave moves forward.
9.) A water molecule on the surface moves in a clockwise circular pattern, the diameter of which is roughly the height of the wave from trough to crest.
10.) The circular pattern of the water molecule is created by the wave energy.
11.) A surfer floating (not surfing) on a surfboard moves no different than a water molecule on the surface right below him.
Now some things to think about. If you think that the water molecules have some sort of extra energy, where is this extra energy coming from? Or do think that flow of the water molecule created by the wave is this magical energy?
Observe a wave, for example a big wave such as Jaws. Pick something floating in the water. Time it as it floats from the trough to the crest. Compare that to how fast the surfer is going. This example clearly demonstrates how insignificant upward flow is to propulsion.
When you pump you are essentially pushing off and jumping (weighting and unweighting) with your board to a higher point on the wave. At the same time the wave is moving forward to meet you. The higher you are on the wave the further you have to travel, and the more speed you will pick up.
But you don’t need to pump to gain speed. Like in a bottom turn you can use the speed of dropping into the wave to carry you back to the top of the wave. If the wave wasn’t moving forward, this wouldn’t be possible.
Even though it doesn’t seem like it, when you pump from behind the whitewater, you are still pushing off and putting yourself a little higher on the wave. Do a lot of these little pumps, and you get enough speed to potentially get in front of the whitewater.
You can’t get much speed pumping straight in, because there isn’t any good way to push against the water. And any pushing efforts are taking you away from getting higher up on the wave.
More speed can be pumped from a bottom turn on the open face than from in front of the whitewater because you are able to get yourself higher up on the wave from an open face.
A broken wave is still a wave, so it still has wave energy, in addition to the energy of the water molecules moving forward. Observe a broken wave and see if you can still see the wave. The wave will continue, broken or unbroken until it is stopped.
Surfing is:
1.) Using the speed of dropping into a wave to help you get higher on the wave (from gravity).
And/Or
2,) Pushing against the water to jump yourself and your board higher up on the wave (pumping).
And always:
3.) The wave moving forward, meeting up with you and lifting you.
So you can jump up higher on the wave and the wave lifts you higher. That’s it. The rest is gravity.
2.) The only water particles that matter to surfing are on the surface.
i think that the whole wave matters
3.) A water molecule on the surface essentially stays on the surface.
I dont know.do they?
untill the waves breaks maybe
4.) There is a difference between the wave and the water molecules.
what?
5.) The wave has energy.
agreed
6.) The wave lifts the water molecules.
water molecules move(liquids) are always moving even in apparently still water,so yeah the waves moves the water
7.) The water molecules have no energy of there own.
ALL molecules have energy
8.) The wave moves forward.
agreed!
9.) A water molecule on the surface moves in a clockwise circular pattern, the diameter of which is roughly the height of the wave from trough to crest.
I dont know .the animation says so ,who else?
10.) The circular pattern of the water molecule is created by the wave energy.
agreed!
11.) A surfer floating (not surfing) on a surfboard moves no different than a water molecule on the surface right below
him.
just a simple example of the influence of other elements on the surfer proves this statement to be incorrect!
ie. air pressure and mass
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do think that flow of the water molecule created by the wave is this magical energy?
maybe
do you believe in majic?
Observe a wave, for example a big wave such as Jaws. Pick something floating in the water. Time it as it floats from the trough to the crest. Compare that to how fast the surfer is going. This example clearly demonstrates how insignificant upward flow is to propulsion.
does it how?
how about a small wave .same forces scaled down
whats your point?
so what do you think is the source of propulsion then?
besides forward velocity of the wave,gravity and flow of water molecules,and muscle power from rider input???
These are facts. I have no opinions on the matter, except maybe the crazy part. Instead of reacting to what I wrote, take some time to think about it. If you can prove any of these facts are wrong, I’m okay with that. I’ll concede. I’m not just trying to be right, I’m just putting out the facts. Go ahead and check them out yourself if you think I’m making them up.
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and forward and downward
We don’t surf on this part. It’s irrelevent.
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i think that the whole wave matters
I’m referring to water molecules, not the wave. We only surf in water as deep as our fins.
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what?
A lot of people don’t distinguish between the two. It’s important to keep them separate.
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ALL molecules have energy
I knew someone was going to bring this up. Yes, you are correct, but we are not talking about that kind of energy, are we. Lets keep it pertinent to surfing.
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just a simple example of the influence of other elements on the surfer proves this statement to be incorrect!
ie. air pressure and mass
Are you talking about wind or something like a boat bumping into him? Lets try to remove variables, not add them.
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do you believe in majic?
No.
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whats your point?
I thought I made it clear. How insignificant upward flow is to propulsion. A small wave is the same. I thought the large wave would be a good example since it has more energy.
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so what do you think is the source of propulsion then?
besides forward velocity of the wave,gravity and flow of water molecules,and muscle power from rider input???
I guess you haven’t read my other posts in this and the other threads. Propulsion is solely from gravity. The wave moving forward is important to lift the surfer to allow him to use gravity as propulsion. Muscle power is indirectly related to propulsion in that it is a means to get to a point to use gravity. Flow of water molecules are insignificant.
gak indeed. I’m not going to read this whole messy thread but here’s what I think:
To surf a wave it takes 3 things acting in harmony:
wave energy
gravity
muscle energy
if a wave is too weak you can’t ride it, no matter how steeply it breaks or which way the water flows. Evidence: try surfing a perfect 1 inch high wave sometime.
gravity - if a wave is not steep enough you can’t ride it. Evidence: try surfing an unbroken tsunami - wave period is so long that you can’t even see the wave; lots of energy but until it gets steeper, no good for surfing
muscle energy - without some speed to catch up to the wave, you can’t surf it. Evidence: just look at all the newbies who can’t paddle hard enough. Yes, there’s the “no paddle” takeoff, but even that involves changing your weight distribution over the board by leaning forward, which uses muscles.
Now quit arguing and go make surfboards, or better yet, go surfing.
Anyone is free to disagree with me; I don’t care, and I won’t get into pissing matches with you so whatever.
PS oh yeah, the magic word is “harmony”… something to do with harmonics, frequency, music, Ambrosian stuff.
Oh ?