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Slalom Course Redesign - a thread for those suffering from B.R.D.S.


Horton
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It is that time of year where many of our minds wander into the "Wacky Zone". Maybe is it the B.R.D.S. talking (Buoy Rounding Deficiency Syndrome - pronounced "Birds")

 

Based on comments that @JimBrake made in another thread @AdamCord‌ and I were talking the other day about a wider course. I think that if the balls were 10 feet wider I could run 15 off*. Balls at 47.5 feet from center and 60 feet of rope. That is 12.5 feet to spare. It would be a challenge but how hard could it really be?

 

@AdamCord‌ tried to tell me that if the balls were only 18 inches wider I would struggle to run a pass. As usual @AdamCord‌ must be wrong for me to be right.

 

(* I would not bet very much on this)

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For what its worth I agree with @AdamCord. If the course was 10' wider you'd look like you were skiing in a cable course pulling quite long after the second wake. Likewise, if you made the course 10' wider you'd need to make the course proportionately longer as well.

 

Either way drop some buoys in that new lake of yours and grab a video camera! If nothing else, it will be entertaining!

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Interesting. Firstly, width is a much bigger deal than rope length. Dr. Jim helped demonstrate that, but it's also clear (ish) from the geometry: 5 feet less width decreases the required rope angle more than 5 feet of extra rope does. (Until they meet when both require the full 90 degrees.)

 

So if the course is 10 feet wider, -28 is gonna be harder than -38 is now. But -15 is probably still pretty doable after getting acclimated. From a combination of science and pulling stuff out of my ass, I think it would be harder than -32 and easier than -35.

 

Try it and let us know how our predictions were!!

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@than_bogan I'm no engineer but agree by seat of the pants. One of the courses I ski is a squeak narrow. It's hard to measure it accurately to see how much given how a person has to measure...but it's pretty close.

 

That course is duck soup to ski. I don't miss 38 there and 35 feels like 32 (only easier). A ski partner who runs most of his 35's by season end but one in a zillion 38's makes 38 there. If I was given a half foot of extra rope, I don't think it gets that easy. I have had legit shots at getting out of 39 on that course...that doesn't happen anywhere else and again...give me a half foot or foot of rope and that doesn't happen.

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The answer is not to widen the course at all but rather enter course right to left after every completed line length. Most sites (except sites with the pesky jump in the way) currently would be able to accommodate a 12 buoy opposite course. run 28 from left to right then right to left before shortening!!
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Dr. Jim's course, in "narrow mode" was about 2 1/2 feet narrow on each side. And, he was

running 41 on it at "record" tournaments. I expect that amount was worth 2+ passes.

Would be EZ to check out on a modified crosslined course with some high-level Open skiers,

both Men and Women.

 

I had a friend, who was not a deep shortline skier, run thru at least 41 on the INT "inner"

course, which is 4 meters (about 13 feet) narrower each side. Was apparently ridiculously EZ.

 

In the wider direction:

Back in 1964, at his ski school in Sarasota, he had one course that was just one foot wide on

each side, which he described as a bitch of a course. At that time, he was occasionally clearing

24 off and getting into 30 off at tournaments.

 

10 feet wider each side would make the course nigh unto impossible for beginners.

 

Note: Chet Raley has the Left-Hand course option at his ski school operation in Boca Raton.

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There is an obscene amount of time at -15 but I'm not sure I could do it at 34, in face 38mph may be required in order to carry speed out to the wider buoy. I'm not sure a longer course is necessary but in terms of width it will feel like skiing -28 but moving a lot farther. So maybe yes to the longer course... More variables than I think o can accurately account for.
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interesting to think about:

 

shortening the rope doesn't necessarily change the distance you have to cover in the same amount of time; but making the course wider does.

 

by making the course 1 foot wider, you have to go out 1 foot wider at 1 ball, come back from 1 foot wider at 1 ball and then back 1 foot wider at 2 ball etc.

 

shortening the rope only increases the angle of the pull of the boat (i.e. the boat is pulling you harder back to center at shorter lengths)

 

by making the course wider (but not longer) you actually have more ground to cover in the same amount of time, meaning your average speed has to increase.

 

with a shorter rope, you still have the same distance to cover in the same amount of time (same average speed), but you need to do more work behind the boat to get free and make it out to the buoys before you're pulled back in.

 

** this is under the assumption that the skier path for 15 off is the same as 41 off. which we know isn't exactly true

 

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just did a little trig because this sparked my interest.

@boat speed 36 mph, if a skier followed the straight line path from buoy to buoy he would travel 293.75 meters in 16.08 seconds = 40.86 mph

if you make those buoys 10 feet wider, the skier travels 312.74 meters in 16.08 seconds = 43.51 mph.

 

so maybe it won't feel so much like the rope is shorter, but that you're going super fast!

 

iwsf.com/rules2004/rulebook2004/diag04a.gif

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@Horton are you really bored or something?

 

The one time I tried a course that had mistakenly been installed with the turn buoys ~1.5 feet too wide, neither @adamhcaldwell or I could manage to run 28off on it. If we had had a longer rope we would have tried it. We found that we could get the ski outside of the ball, but there just wasn't enough speed/energy to carry you back to the line. Maybe with some serious practice and a different ski setup it can be done, but NO ONE is running a pass at 15off with the buoys set 10' wide.

 

If you stretched the course and used a ski that had insanely low drag, like a trick ski, it might be possible.

 

I also once tried a course where the buoys were I think ~4 feet narrow. Running 43off was easier than 15off on a normal course.

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Over the years there has been some occasional discussion about very short line being unfair to shorter skiers. One thought other than messing with the width of the course to change things up would be to keep the width as-is and reduce the distance between buoys from 41M to 40M- that might make things interesting...
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Many years ago back in Ohio I skied on a portable course on a river and was able to get 3 @ 35 off. At that time I could barely run 15 off at 34 mph. We measured the course arms when we got done skiing and the turn balls were 16" narrow on each side. Course width makes MUCH more of a difference than the length of the rope. I sure miss that course......:)
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When I first mentioned this to @AdamCord‌ he gave me some crap answer about how who ever designed the course must have spent a long time thinking about it. @Edbrazil‌ will correct me but I assume it was semi random. A standard rope was 75 feet long and the balls were originally exactly 1/2 that wide. (37.5 x 2 = 75 for this of you in Minnesota).

 

I have trouble finding the time to try this kind of wacky crap but I really want to.

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@drew It is not super cold at your house. Drop in some balls and get us some video. It will give you an excuse to show off your pretty green ski.
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What I do love about this thread is the comments about how 6 inchs of width on the balls can totally change scores. Brings me back to another thread...
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I remember hearing a comment that @Mapple made about how running 41 is easier now than when he did it the first time because the buoy tolerances have gotten smaller thus moving the course in. If I remember the rule book correctly the course is measured to the middle of the buoy and not to the outside edge so the distance we think we are traveling is actually less than what we have to travel to get around the buoy. @Edbrazil‌ I'm sure would know the exact numbers
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@mattp Over the years, the buoys have gotten smaller and smaller. Most recently, the skier

buoy allowed minimum diameter has gone from 23cm to 20cm. That, along with buoy height,

makes the course 'easier', even though the half-width has stayed at 11.50m. One top skier

estimated that every inch a buoy is lowered is like moving it in 4 inches.

 

23cm was around for a long while, but back in the mid-1970's, I remember that for a World

type certified course, they had to be something like 35cm. Trying to inflate AWSA buoys to that

size tended to make a lot of them egg-shaped. Or, they might even EXPLODE.

 

Even farther back, before accurately measured & surveyed courses, you might encounter a wide

variety of 'buoys'. Clorox bottles were somewhat of a standard at one time. But, you might

have other types, such as half-inflated inner tubes folded twice. Or, mooring buoys. You sure

wanted to stay way away from them.

 

Note that when we went to metric dimensions, the SL course got a bit harder. Gate to gate went

from 135feet to 41meters (~134.5'). Endgates went from 90ft to 27m (~88.6'). Overall length

from 855ft to 259m (~849.7'). This was in the mid-1970's. Until the mid-1960's, of course,

the endgate spacing was the same as the gate-to-gate spacing. Good for us wallyskiers, but

the top shortliners wanted the shortened endgates. First tried out at a Masters, circa 1963.

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@Than_Bogan thanks I thought the caliper yoda was clever :D

 

@Edbrazil do you know how the original course dimensions were determined? I imagine there was a LOT of trial and error. It could just be that I'm so used to the way it is now but anytime I've skied a course that's even a little bit off it just feels wrong.

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I've seen pictures/video of the 1939 Nationals (1st Nationals), where there was a line of waist-high buoys to weave around. Chuck Sligh is credited with designing the current model of the

slalom course for his 1947 Nationals. See:

http://www.usawaterskifoundation.org/#!charles-sligh-jr/c2440

 

Unfortunately, about everyone from that era is gone. Sometime, I'll have to get over to USA

Waterski and look up old Rulebooks, to check out the printed SL course dimensions.

 

Stew McDonald (RIP) had plenty of olde tyme stories. One was about the first use of shortline,

when there were at least 2 tied with perfect scores at the top speed. So, they decided to shorten

the towline. 6 feet was suggested, but thought enough, so they took 12 off. This may have

been at an event at Cypress Gardens in the late 1940's or early 1950's.

 

Noted raconteur, ski maker (Aqua Sport), and former AWSA President Larry Brown wrote a

Water Skier article at one time (late '50's, early 60's?) favoring the Random Slalom Course, where

there would be no set dimensions for the course-setter, somewhat similar to the way snow ski

courses were set. But, to approve the course, the Chief Judge would have to be able to run it at some speed. Think that Larry was also advocating combinations, like flushes on one side.

 

This video from 1954 shows Alfredo Mendoza setting a 99 ft. record at the time in the Dixie

Tournament, but toward the beginning, it shows Dick Pope Jr. running a course that had a

zig-zag on one side. Not a very fast speed, maybe 30 or less. See:

 

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I think that the weight of influence of both skier height and boat path become slightly reduced if the course width is increased. The geometry will become more difficult, and will require more skill (rather than jus raw reach). The warm-up passes (whatever they may be) would become less "given", and keep everything interesting... we would see an increased premium placed on efficiency.

The current metric course dimensions have served us since the 70's? Think of the equipment advances--skis, boats, speed control--plus, as mentioned earlier, the smaller buoys have essentially made the course narrower. Video analysis and controlled conditions have reduced the "mystery" of how to get it done. Things may have gotten a little stale as far as how challenging a successful pass (any pass) ought to be.

Compare to golf--yes, the equipment is much improved--but the courses are also five to ten percent longer than forty years ago.

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@drew I can not say I have ever found the present course to be stale! There has to be some success to be had to keep interest. How much of a width change are we talking here? Changing dimensions would just further increase costs in a sport where costs are already out of control for us average Joes/Janes. When skiers start running -43 regularly then maybe but I don't see that happening soon. If changed what happens to the records? Start from scratch?
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Tom, my comments are intended only as food for thought, and to a certain extent I agree with much of what you are saying. Costs ARE prohibitive in this sport--any change that I am suggesting we consider would involve only widening the skier buoys 0.5m.

I am not saying the event is broken by any means--but it may be better, more interesting, more challenging, if the course were a little tougher, that's all.

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I know that Drew, as are mine. I guess I am just resistant to change. Also, I am just lazy and don't want to add half a meter of pipe to my floating course. Not a big deal for me but some guys have trouble with anything mechanical. Also, even a small change would require all record courses to be resurveyed.
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I can't say that I support any significant SL course dimension changes, although that would be a

goldmine for me and my course work. But, I would like to see the endgate/scoring situation

fixed so that it doesn't take lots of buck$ for video gear for this one small part of the pass.

 

There was a proposal last year originated by Chet Raley that got shot down by the Rules

Committee, even though it was just going to be for Class C events. Essentially, this idea was

that you had to start from the 2-4-6 side of the wake after the 55m pregate to get credit for # 1.

Gates would be for boat driving reference, and maybe also a requirement exiting the course.

But, no video requirement.

 

Meanwhile, if you can get 1/4 buoy, why not 3/4 ? Such a score would be when a skier did

what used to get you a full buoy a short time ago, which is to return to the wakes with slack,

and then throw the handle. Would help eliminate some ties, and give a skier an alternative

to trying to take the hit from a pile of slack. Back a few years, the Tour ran a qualifying round

with the 3/4 buoy rule exception used.

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