Slalom Course Setup Pictures

[Skoot1123]

Ok Ballers - we are getting close to getting the retractable course for our lake finished. We surveyed our course and fine tuned it before making it permanent. But basically what we have done was take 4' long earth augers and screw them down into the ground with a post hole digger. From there we took old 5 gallon buckets cut the bottom off, slid it over the earth anchor and filled with concrete. We drilled some plastic pieces to bolt around the earth auger so the stainless mainline could set nicely inside and have a smooth pull when we hook up the winch. The "stringer" lines (which go to the boat guides and turn buoys) will be attached to the mainline such that it will all pull down together. Our mainline is 5/16" SST cable that is 7x19 strand wire. Our stringer lines are 3/16" SST cable that is also 7x19 strand wire. Will be threading up the mainline (for about half the lake as the other half has too much water in it - still draining until the valve is shut) tomorrow and hopefully the stringer lines as well. We plan on putting sub buoys on about all the buoys to add some extra buoyancy and help with buoy replacement as needed. We'll probably have to go with the standard sub-buoy but didn't know if there were others out there. Will use surgical tubing from sub-buoy to the turn buoys and boat guides. Any other suggestions or questions?

 

Big thanks goes to Ed Obermeier who we got our course buoys from. Great to talk to, super helpful, and SPEEDY DELIVERY! To our house in two days. Some awesome coozies to boot!

[Edbrazil]

Even I can't quite understand the setup. Will this end up being a permanent bottom-anchored

course with individual anchors? On a private lake? More details and/or pictures, please.

 

And, where are you? Presumably somewhere in the US.

[Skoot1123]

Ed - I am trying to upload photos. They must be too large. Working on it.

[LakeOneSkier]

I'm curious... why use surgical tubing?

 

They had it on the course I now ski at and I replaced it with 1/4 bungee after my first year here. The surgical tubing seemed to get pretty slimy and would come loose fairly easy when hit by the weekend warriors and their tubes.

[Skoot1123]

Surgical tubing as opposed to wire for the polyform buoys. Have seen it done elsewhere and it works pretty slick. Time will tell how slimy it gets!

[The_MS]

Surgical tubing gives the balls more flex or movement. We use bungee for the boat guides (yellow-green) and tubing for the skier balls (orange-red)

[Skoot1123]

 

Finally got the pictures to load. Hopefully this makes more sense.

[Zman]

Just curious, looks like a private ski lake, so why the need to retract the buoys? Pretty cool though. Did you consider partially filling the buoys so it would take less force or tension on the mainline to retract? Could probably use less than 5/16 cable - but it should sure last a long time?

[MISkier]

I believe the retractable course is desired to allow the lake to support non-slalom activities that require more open water.

 

I've been wanting to so a system like this on my public lake to avoid have to install and remove a portable or swim to attach buoys to subs. We have a requirement that the course has to be out or submerged overnight. The lake is relatively weed-free, about 6-8 feet deep where the course is, and a hard bottom.

 

@Skoot1123, I like the design.

 

 

[Skoot1123]

Ed - we are in Illinois.

@MISkier‌ - thanks! It is a combination of my father in law and I putting our heads together and coming up with a design.

@zman - we wanted to be able to pull the course down for when we barefoot and pull the kids tubing and the occasional wakeboard session.

[mwetskier]

never built a lake before myself but it looks to me like it should be deeper and wider so i recommend adding more water.

[jipster43]

That's awesome @Skoot1123 ! What are the dimensions of the lake? How deep? Any turn islands?

[LeonL]

And what are you going to use to pull all this buoyancy down? Seems to me like a hard pull. That is, if I understand the plan.

[tugboat]

Where at in Illinois? I am looking for a ski lake near St. Louis

 

[Edbrazil]

Looks interesting, although a bit bizarre.

 

Just don't set up any Dr. Jim deal there. I predict that it will be a good bit of a technical

challenge to get it all to work smoothly and consistently. One hangup might be when

you try to release the pulldowns, and want it all to spring back into place accurately.

 

If you want the course pulldown to be from a single point, I believe you will have plenty

of work to get it right.

 

Yup, looks like the water level needs a few feet added. Pumping in? Or waiting for rain

and Winter snows?

[Skoot1123]

@jipster43‌ - the lake is 2,000 ft long x 240 ft wide. We have islands at each end - 100 ft diameter each with another 100 ft of water between the island and the shore. The average depth is 8 feet with a fishing hole that is about 20 feet deep.

 

@mwetskier‌ - no kidding!! Need water, buy not until we have the course in.

 

@leonl - we will use a winch to pull it down. We pulled the mainline through today and even without water it pulled very well. The plastic guides alleviate the friction with metal quite a bit.

 

@tugboat - we are 2.5 hours from St. Louis.

 

@Edbrazil‌ - good questions. It is a permanent bottom anchored course. There is no way we would make a Dr. Jim course - defeats the purpose. When we pull the course down it will be a maximum of three feet from the lake level (we built in adjustability for water level) and there will always be tension on the main line and stringers. I can take more pictures and share tomorrow.

 

Anyone have ideas on bigger sized sub buoys?

[jipster43]

That sounds awesome @Skoot1123 ! I like having plenty of water room around the turn islands. When I watch beginners or kids spinning a tight sqeeze around an island, my hands tend to sweat.

 

The Broho is roughly 2000' long and it skis perfectly. I look forward to viewing your lake on Google Earth!

[crashman]

That looks great! Were you able to sell soil? It seems like there are some good ski lakes to be made in the Midwest while selling the soil to cap brown fields. Is it just you and your father-in-law or will there be others? There is a wakeboarder on our ski lake and if he started to jack with the course while I was getting ready to ski I would probably blow a gasket.

[cragginshred]

Sounds plenty big to me. Must be nice!!! When can I visit?

 

[Edbrazil]

Subbuoys: @skoot1123 How big are you looking for, as in how much displacement floatation?

One source is the fishing supply place in Miami: Atlantic & Gulf. They are also somewhat

familiar with dealing with water skiers. Website: www.atagulf.com

[klindy]

@Skoot1123‌ Buoys and sub buoys with surgical tubing in between....I'm going to guess it'll take 25# +/- at each buoy to get them submerged. 22 buoys in the slalom course x 25# is 550# on a single line assuming. My calcs are close. Certainly doable. The problem will be anything elastic between the sub and the surface buoy. You'll need to pull all the 'slack' out of them before they go under. Depending on length and elasticity that could 3-4' easy. Again doable but it'll be a bear to get to work on one line.

 

Not sure where you plan to put the winch relative to the lake (center, end, other) but I'd advise breaking the course into 6 or 7 buoy clusters and use 3-4,winches. Getting the cables strung now is easier than it'll be with water.

 

 

[Zman]

@klindy‌ That's why I was thinking he might consider filling the turn buoys and gates about 30-40 percent with water. Keep the sub-buoys very small like the ones from skier-to-skier (link below).

http://www.skiertoskier.com/contents/en-us/p13.html

I think I would skip the bungie, or at least use a cord with minimal stretch for just the reason you stated.

As for the buoyancy per buoy. If he uses all round buoys, each of those inflated to 8 inches would displace a little over a gallon of water. The buoyancy equals the weight of this displaced water, or about 9.7 lbs. The sub buoys from S2S would only have a buoyancy of about 1.3 lbs. So, a total of about 11 lbs. plus some friction pulling the cables through the plastic pieces he shows. So, I would estimate somewhere between 12 and 14 lbs per buoy. He could reduce this by about 4 lbs for each buoy partially filled with water

Even at a high estimate of 15 lbs, 26 buoys, that's only 390 pounds of pull on the main line. His 5/16 SS cable has a design break strength of 9000 pounds. He should be more than good.

[Skoot1123]

Got some more pictures of the mainline setup today. As you can see the line is pretty stout! We are utilizing a mechanical advantage by having our "splitter" about 8 feet south from where the boat guides are positioned. There will be a few spots we'll have to smooth over so as not to bury the cable when we pull it down the first time. (We are thinking ahead - the position we have it in is the "skiing" position so if it is stuck, at least we can ski!) I know we'll learn something the first couple times we use it.

 

@klindy - good point about the sub-buoy to skier buoy line stretch. We were thinking about 6-8 inches of surgical tubing from sub-buoy to skier buoy. We'll determine that once the lake is filled and the milk jugs are floating. We left ourselves with small loops of stainless wire to work with so we can service/replace stuff on them easier (especially in cold water).

 

@zman - I'm not sure if the buoys are equal to a gallon of volume as I haven't run the numbers, but a gallon of fresh water is roughly 8.45 lbs. One buoy therefore would be equal to 8.45 lbs of buoyancy (if submerged completely). The sum total of stainless cable weighs ~ 250 lbs. Due to the volume it takes up, it will only weigh ~ 246 lbs when submerged in the water. We certainly aren't worried about the cable breaking - if it does, then we have other serious problems!!

 

The "little" sub buoys would be mainly for support to help lift the line off the bottom of the lake. We don't really need to float it since pulling the line through the plastic blocks was pretty easy. Thanks to @Edbrazil‌ for the recommendation. I'll be taking a good look at those!!

 

[Zman]

@Skoot1123‌ No worries, but I know what water weighs. That's how I got to the buoyancy noted - as noted 8 inch buoy is a little OVER one gallon. Certainly you have no reason to worry about cables breaking - your cable won't even be breaking a sweat with pulling down the buoys. That's an incredible system and design you have.

Check out the link to skier-to-skier I had in my last post. I think the sub buoys there will work very well for you. Inexpensive, hold up very well, and perfect for keeping you buoy anchor lines close to the surface when you need to replace a buoy.

[Bulldog]

looks like a very well built system!! Shoot some video and post once it is doing what you want it to do please...

[Skoot1123]

Thanks guys - @zman - your correct. An 8 inch diameter buoy is a hair over one gallon. Any little bit will help us!

 

@Bulldog - thanks! I will be sure to shoot some video when we pull the ball system down the first time. Should be pretty interesting...... Will have to go out in the water and verify all the anchors held in place though!

[thompjs]

Attachments of cables -- Do not saddle dead horse. Look it up.

 

I tried this type of system and eventually silt on the bottom created too much drag. Good luck.

 

Also bungee stretch led be to believe that I needed about 12 foot of water to make it work.

[thompjs]

http://www.thecrosbygroup.com/Portals/0/docs/manuals/9992320.pdf See page 115

 

 

[Edbrazil]

Go to www.atagulf.com And then search "floats" If you're looking for subbuoys.

Lots and lots of alternatives.

 

Thinking that you may want their FLTYQE-3 Good price.

 

Which is yellow football-type float with 11oz. buoyancy, and does not absorb water. I've used

them, but mainly the larger version FLTYQE-6 With 22 oz. buoyancy, and typically for bottom-

anchored courses in relatively shallow water.

 

You sure do want some buoy breakaway feature. For no stretch, could be mason line or

small diameter bungee cord. But, best might just be a short section of the typical rubber

tension band, such as a foot or less in length. As available from SkierToSkier or WallySkier.

[Golfguy]

Skoot1123 We are about to build a new lake in Arizona and are wanting to install a retractable slalom course. I have been looking at your design here in the forum and now wonder how it is working for you. Any comments are appreciated.

[Skoot1123]

@Golfguy - the submersible course works! However, we had a setback when one anchor pulled out of the bottom. (it hit rock when we were drilling them in) With that said I would recommend the following:

 

- We used auger anchors for the mainline cable - they work but they need to be solid in the ground (we did reinforce with concrete)

- Sub-Buoys: don't go overboard with buoyancy. We have 8 or 9 5 gallon containers that we sealed up and put a hole through the center of. They work fantastic, but honestly that is tooo much buoyancy. If we used normal sub buoys from skier to skier or fewer 5 gallon buckets we would have been better off. (IE: much less force to pull the cable system down)

 

If we had less force required to pull the system down, we may not have had the earth auger issue.

 

Let me know if you have any other questions. I'll be happy to answer!