SkiJay

@Wish & @Brewski There was a LOT of research into fish, whales, exotic sailboat keels, rudders, etc., plus aerodynamic studies since air and water are both fluids. But I had to draw the line at renting hydrodynamic test tank time before these fins ended up costing more than skis. In the end, applying what I'd learned to ski fins took a mountain of experimental fins, the help of a wide range of skiers on a variety of ski brands and a torn hamstring on the prime crash-test dummy. It has not been a cheap or frivolous project, and the size and shape of every hole in this fin is the way it is for a reason.

@AkBob You can preorder one now at: https://WhisperFin.com. I'm expecting to have fin's within six weeks, and will be filling orders on a first come first serve basis.

@kc, @DavidN & @ToddF There are two thicknesses, .080" and .095". I broke it down by brand for my own records. The fin profiles are identical in every regard. The profile along the top of the fin is designed to work in all of the current common fin blocks, including the new Connelly Viper design. Additionally, the prototype fins were all .080" and they worked fine in every ski listed. So if you want one fin to work in all skis, choose the .080" thickness. FWIW, Bruce Dodd set a Men's 6 national record last month using a .080" fin in a Goode which normally uses the thickest fin.

@scotchipman There are no formal arrangements with any ski manufacturers at this point, but I'm open to the idea.

@scotchipman I don't know where to start with that question. How about with a picture. In a nut shell, for turning, a small fin is better (that's a whole topic), and for acceleration, a big fin is better (another full discussion). With these turbulation slots, this fin achieves both goals, turning and accelerating better than the standard fin.

@6balls Exactly! We used to use zigzag tape as turbulators on our competition sailplane wings, and the glide ratio would improve remarkably. It seems counterintuitive that creating turbulence can actually reduce drag, but that's how the turbulator slots on this fin work.

@Zman This isn't a question that has a right answer. It depends on your initial setup. If your setup is a bit loose, it may run -28 and -32 nicely, but start over-smearing into too much angle at -35. In that case, what @AdamCord said. If your initial setup is a bit tight, you can force enough turn turn out of it to run -28 and -32, but at -35 the boat will have you before your turn is finished. Less tail hold would be the fix here, and that may be bindings back, less fin area or both. Like @liquid d said, do whatever makes the ski work best for the hardest pass you make more often than not. That will give you the most shots at your hardest pass and a ski you know and trust when pushing the envelope.

@grab2go What you say makes sense, but it's not that simple. I've experimented with wing locations all over the fin without encountering the same change in instability. I suspect it's got more to do with the same principles that make jets with forward swept wings inherently unstable. An airfoil with a straight leading edge is very efficient at low speeds, but gets progressively more unstable as speeds rise. Small planes have straight leading edges, fighter jets need the leading edge swept back for stability. And since water is 800 times denser than air, our flow dynamics may be closer to near super sonic air flow than not. The ski pro used the term "abrupt" to describe the ski's pitch behavior. Pilots refer to unstable pitch control as "snatchy." Similar descriptions for similar behavior???

@DangerBoy & @adamhcaldwell Curiosity got the better of me, so we tested a backwards wing. And I said "we" because I solicited the participation of a ski pro with unassailable testing credentials. Notice that the leading edge of the attachment flange has been chamfered to focus the test on the shape of the wing itself. The results weren't as extreme as described by Adam, but his prediction was closer than mine. As I expected, drag increased hardly at all, about the same as a ¼° increase in wing angle. But as Adam described, ski behavior changed quite a bit. Transitions like the edge change became abrupt enough to affect skier balance—not enough to threaten the pass, but enough to know something wasn't right. So there you have it. A rearward swept wing is both more stable and more seaweed proof than a forward swept wing.

Most skiers tune by feel. But feel can be very misleading. When the tail feels too loose, there may be too much tip in the water which makes the tail feel loose relative to the tip, or the tail may not have enough support despite a perfect tip. Both of these feel so similar they can lead to poor tuning decisions. These tuning miscues then lead to proclamations that shallow is better than deep or vice versa, when in fact one setup was just better optimized than the other. When I'm tuning from the boat or from video, I can see if the root of the problem is tip-engagement, tail support, or skiing technique, then fune-tune accordingly. And when properly optimized, shallow and deep setups perform and feel very similarly. So similarly that when blind tested, I've had pro skiers guess incorrectly which one was which. In other words the deep setup felt like it rolled more and easier than the shallow setup—and ran the same number of buoys. I can explain why these FD extremes roll so similarly another time. Where a very subtle difference remains is at the finish of the turn and through the edge change. If there are differences elsewhere in the pass, one of the setups is better optimised than the other—so go with the best one. And that's why I bother, @Chef23. To demonstrate how similar these too FD extremes are. Then the skier can pick whichever one seemed best, fully optimise it, then forget about the whole debate and ski—happy in the knowledge that the grass isn't greener at the other extreme of FD.

If you have a favorite long/shallow or short/deep, here's a handy formula for making a big change and ending up with a ski that still feels pretty familiar: FD∆ x -2.3 = FL∆ (where ∆ signifies "change") Say your setup is: 2.450, 6.960, .760 and you want to try FD = 2.510. FD∆ = 2.510 - 2.450 = .060 FL∆ = .060 x −2.3 = −.138 New FL = 6.960 - .138 = 6.822 And the short/deep setup would be: 2.510, 6.822, .760 This generalized formula works remarkably well on most skis, and even if it's not perfect on your ski, it will get you close enough for minor fine-tuning.

Rather than a large hole or slot for one end of the wing to move up and down in, perhaps he had a series of strategically located holes in the fin that achieved preset wing angles—no wing gauges required.

It looks like an early wing that predates the popularity of phillips screw drivers.

I'm certainly no stranger to looking the idiot on the dock myself, @DangerBoy. I've tested something different nearly every set for 300 to 400+ sets per year for over a decade now. And by "testing" I mean complete with written hypotheses, impressions, video analysis and notes. You're right, I used the words "probably" and "may" specifically because my comments on the forward swept wing were a guess, but a somewhat educated guess. And I thought it obvious this test would be a waste of time because even if there is a benefit, it's moot because of the certainty of hooking and dragging clumps of seaweed down the lake with anything on a ski that is swept forward.

I bought four sets of these plastic gauges about a year ago, then through them in every boat glove box I spend time in. They work great, don't rattle around or damage the glove boxes, and the set I attached to the dock at Predator Bay spent all summer in the sun with no damage. I prefer using my full sized aluminum gauges, but for $5, these plastic gauges are one of the best deals in water skiing. If you just want a FREE paper or cardboard gauge for a quick measurement, you can download a set that you can print on your regular paper printer at: https://finwhispering.com/shop

@BraceMaker & @DangerBoy Wings on supersonic jets have traditionally been swept back for reasons of drag and stability. Forward swept wings are so hyper-maneuverable that a human pilot couldn't keep up with the original designs that sought to gain maneuverability at the expense of increased drag. Modern computing power tamed the inherent instability of forward swept wings on some experimental fighter jets. But since modern jets are so stunningly maneuverable anyway, the designing in a drag penalty is unnecessary. If you put your wing on your ski backwards, there may be some infinitesimally small increase in tip pressure at the same wing angle, but it's probably the equivalent of a one quarter degree wing angle increase—kind of a pointless reason to look like an idiot on the dock.

@DW 6061 aluminum

@tjm Of all the factory spec numbers, binding location is the most meaningless. With binding stiffness, rear binding choices, measuring techniques, foot size, height, weight, and unique skiing techniques all contributing to the mix, binding location is more personal and often more critical than fin setup. If you like your new location better, then it's better. Factory recommendations are just an average starting point.

Thank you for all this feedback. Most of the wish list above is slated to be addressed in a future book that's currently in an advanced stage of outline. It will be all new, more concise, and will take a different approach to the subject altogether. But it's still thousands of hours away. It's been delayed for nearly two years now by ongoing research into a new fin design. Meanwhile, the decision at hand isn't about the content or format for the existing book. It's about a simple update and reprint. There's still steady demand for the first book as word spreads beyond BallOfSpray, but it may not be enough to justify an economically sized printing order. That's why I'm asking how many of you would be interested in purchasing a second edition if ⅛ of the book is updated to include what I've learned over the past three years of research and tuning skis for a living. And yes, there may be an electronic version later on.

The first printing of Fin Whispering is nearly sold out and I’m trying to decide whether to do a second edition or not. Most of the general prep info would remain the same, but about 1/8th of the book would be rewritten to update concepts, procedures and formulae for binding and fin tuning—aka the important stuff. It would be a lot of work and small runs of books are very expensive, so I’ll only go ahead with this if there seems to be enough demand. Your vote won’t be made public, and your help with this decision would be much appreciated. Many thanks for all your support to date.

Something to keep in mind is that the the half of the fin block touching the washer will deflect upwards significantly unless the fin is clamped into the block at all times. For example, if the fin block is clamped to the fin at the time you loosen the block from the ski to insert the washer, the fin block will be extremely rigid and will force that half of the ski's tail to do most of the deflecting. But if you later loosen the fin to make a fin adjustment, that half of the fin block will deflect/warp upwards significantly with an equal loss of ski deflection. Fin blocks are soft aluminum and will deflect more than the ski unless clamped to the fin while inserting a washer to bend the ski. So if you are using this washer technique, you should commit to always making fin adjustments the same way. I would add the washer with the fin tight. Then I'd make adjustments like this: remove the washer, measure the fin, adjust the fin, tighten the fin, replace the washer—for every fin change. Or, I'd figure out how to get more over my front foot during onside turns so I don't need the washer. The following gif illustrates how a RockerBlock (the stiffest of all fin blocks) deflects more than the ski if no fin is clamped in it during installation.

Most of the top Florida skiers on Radar plates do not use the spacers on either the carbon or aluminum Sequence plates. Personally, I prefer to bolt the front four screws down to the ski with no spacers, but use the floating spacers in the rear. Bolting down the rear stiffens up the back of the ski significantly. I like the tight arcs I can carve with a ski that's a little softer in the tale. Others prefer the stronger acceleration a stiffer tail delivers. I'd say try both ways and decide which you like for yourself.

@lakeo The ridge is a design byproduct, not a performance feature. It's the unavoidable byproduct of a design that sought to put a tunnel tip on a concave ski without changing the radius of the concave from tip to tail. The flat rails that run forward of the ridge to the tip form parallel edges to the concaved section of the tip (called a tunnel). This tunnel reduced tip bite helping the ski maintain outbound direction later in the pre-turn. On the earliest version of this design, the ridge didn't go from one side to the other; it blended into the ski's base quite quickly. This blend required the radius of the concave to be tighter along the tip than it was down the rest of the ski. If I'm not mistaken, the radius of the tip contour was 10", and the rest of the base had an 11" radius concave. This design still left the tip with a bit more bite than intended. So the next version of the ski had an 11" radius concave from tip to tail. But to keep the edge rails, there had to be that ridge running from one side of the ski to the other. The end result was one of the most forgiving tips ever put on a water ski. It didn't deliver as much tip pressure as some aggressive skiers wanted, but you could inadvertently dunk the whole tip into the water mid-turn without suffering pass-ending tip-grab.

Setups are a LOT more personal than most people realize. Over the weekend, I set up a Vapor for a very good, lifelong skier who was down two passes from her norm while demoing a Vapor on stock settings (and again, I think the stock Radar settings are excellent). .042" more DFT later (and minor other changes), she was two full passes better on the ski the next set. Nothing in this thread would have suggested she try a change that Significant. My point is, I'm never surprised when someone begs to differ on what a good setup might be. And it doesn't matter if it's Goode, D3, HO, etc. Personally optimized numbers can vary dramatically from one skier to the next, and êven more so when switching brands.

@Horton Which ski did you not like the long/shallow on, the 16/17 Vapor or the 2018?