Advice on permanent course installation

[jdk99]

Just picked up a new lake and we need some advice on installing a course. 2500x225. 30'deep. Sits 50 feet below grade with steep walls but 5 :1 to 10:1 at water level from erosion.

 

@oneski suggested I look to you all for some pointers for permanent course installation. Would appreciate any input you might have, from the very basics of installation to subtle pointers. Links/previous threads would also be appreciated.

 

Thanks all.

 

 

 

[PatM]

Don't know where your site is located. Does it ever freeze there? If so its easy through the ice.

[thager]

Wow, Nice, but it looks about 50 feet wide

[kurt]

exactly like @ob1 said; however to make it easy on the diver have a pole that is as long as it is deep with an arrow screwed to the pole at the top and at the bottom where the diver is, (both pointing the same way). That way the diver does not have to come up and down a hundred times the boat crew just rotates the arrow which way the diver needs to move the anchor to make it perfect with minimal up and down diving . It works best if the arrow pointer on the divers end is a couple of feet up from the bottom so its not in the silt.

[oneski]

What is the size and dimensions of the concrete/rebar that is used for anchoring sub buoys?

[BRY]

Nice site! Doesn't look 225 wide but 2500x225 50' below grade is freaking perfect.

 

+1 for @OB1 using a portable first to determine best position.

 

30' is doable but seems pretty deep to deal with anchors. Too deep to safely free dive. Also needs lots of tension (to sub buoys) to keep straight or any asymmetric wind will push it out of alignment. I think cables side to side, like at Okeeheelee, is a better way to go. Anchors (fence posts driven in work well) are in knee deep water so easy to adjust/repair/maintain. Handles fluctuating water levels very well also. Keeps 4X courses in record tolerance with the crazy, continuous water fluctuation from FL rains. I believe Miami Ski Club uses same as well, think 5 slalom courses there.

[ntx]

I like to use stainless eyehooks into concrete. They don't rust or corrode like rebar. I also like plastic chain instead of PVC adjusters and rope. More expensive but worth it.

[jdk99]

Yeah, the photo is deceptive. I'm standing about 70' above water level and the iPhone photo makes it look narrow. Lake is actually 3400 long but western 900 feet is <175 wide. Eastern 2500 feet ranges between 215 and 275 wide.

 

Great input guys. Much appreciated. @OB1... Really like idea of using portable as starting point. Also like cross course cables as described by @bry....that's how our club lake is set up. Might combine the 2 .... Use the portable to establish location for cross course cables. Thoughts?

 

 

 

[BRY]

"but western 900 feet is <175 wide" hmmmm, trick course also?

[jdk99]

Is there any reason why one couldn't just anchor the portable course at every buoy then place sub bouys? Seems this would be a little easier than cables and yet would prevent the potential asymmetric drift with individual anchors in deep water referred to by @bry. Anyone tried this?

[Edbrazil]

 

30' deep makes it a bit "interesting" with installing a bottom-anchored course. ?Where is this site

and does it freeze over in Winter? Some good comments by @OB1. Starting with a floater could

be a good idea. 2500' is plenty of room, so you might want to offset the course toward one end

or the other, depending on winds.

 

Might be an appropriate site for a crossline course, especially if you are contemplating running

tournaments, especially above a Class C. I have some designs for an improved crossline design

that we worked out over the years at the Miami multi-lake site.

 

How about some GPS coordinates, so I can find the lake on Google Earth? You can do some

surprisingly accurate measurements in Google Earth.

 

For that depth, to minimize diving, you should fabricate an "anchor wanker", if through-ice is

not an option. I can furnish some pictures. With that device, you can get buoys adjusted from

the surface to typical accuracy of 4 inches, and minimize SCUBA diving and amounts of adjusts.

 

Of course, if the bottom is uneven, rocky, stumps, etc., a bottom-anchored course can be a

problem to install accurately. One of the advantages of a crossline design.

[PatM]

Take a trip to Okeeheelee to get a look at their cross course set up. Real nice and easy to be accurate.

[9400]

I'm a big fan of crossline courses, especially on a site like that.

[jdk99]

Great input guys. Thank you. Located in Midwest so decent ice intermittently.

 

@Edbrazil PM'ed you re: your post.

[9400]

@OB1 if I understand correctly, you had to line up each individual line to the buoy?

We used a 2" PVC pipe and measured out the boat guides and the turn buoy on the length of the PVC pipe. We drilled and installed stainless eye bolts at each attachment point. Line up one buoy on the intended line and all 3 (boat guides and turn buoy) are all the correct spacing. This way there is only 1 sight line down the lake (except for the gates). It would be interesting to see all the different methods for a cross line course.

[jdk99]

Very slick @OBI and thanks for details. A few questions:

 

1) I assume threaded PVC and Cap?

2) Are those 10lb weights? and how many per line?

3) No subs? Have you seen this used up north where winter buoy removal is necessary and, if so, how was the system modified.

 

Great stuff - much appreciated

[jdk99]

...one more thing @OB1, what is 'the small pvc handle pull up and down method' to which you referred in your earlier post.

 

Forgive the ignorance, never done this before :)

[Wish]

70 feet above waterline and steep banks makes for a challenging boat launch. Is there a place to put in a boat that does not require a crane? Wow what a nice site.

[jdk99]

thanks @wish. yeah...nice smooth grade coming down the banks of the spillway from the retention pond to the North. Finishin the ramp next week. No cranes necessary!

[wtrskior]

if the lake freezes, just use subs.

[Edbrazil]

What OB1 is describing a design that was worked out for the Miami site (5 SL courses), over a

period of years. An eventual upgrade was to use stainless coated "Accufloat" cable for most of

the crossline. Big advantage over earlier designs is that each buoy floats independently. No

messing around with bricks here and there, and no problems with one gate being high and the

other being low. Good that he has a picture showing the PVC "slider". Essentially take a 3/4

sched 80 PVC pipe nipple at least 8" long, better 10" or 12". Cut in half to make 2 sliders. The

nipples are threaded both ends. Here is a view of what the system looks like in the water.

With this design, the crossline tension ends up to be significant, like 80--100 lbs.

 

 

[Edbrazil]

However, through-ice looks like an option for the site. Attached is a .pdf of an article that I wrote

for WaterSki Magazine many years ago. Page 4 has some good sketches of the ice method. Some

of the other advice there is a bit outdated, since the article was published over 20 years ago.

 

 

[jdk99]

Excellent stuff guys. Invaluable for my task at hand. Greatly appreciated.

 

@OB1, the "disagree" on your post above was obviously an error on my part.

[jdk99]

@OB1 Educating me in many ways today :)

[Edbrazil]

Looks like the WaterSki mag article didn't get attached. .pdf file. Trying again. And, here is a

picture of a typical bottom-type anchor. "Cored Chimney Block'. The hollow flutes are good for

either driving rebar through or for mud to mush up into, both help hold it in place.

In the chimney block, pour more concrete. Ends up maybe 110#. Note stainless steel eyebolt.

And note that the concrete doesn't totally fill the center, so the eybolt doesn't protrude, and its

easier to stack them for transport.

[Edbrazil]

The cored chimney blocks may be hard to find. Here's a picture of plain ones, 12" and 16"

outside dimension. 8" tall. Beer can for size reference! Also called "pileaster" blocks. The

larger size with concrete will get to around 130#.

 

 

 

[jdk99]

@OB1, you can fly in for a set anytime. Hopefully you can educate me on skiing as well. I just hope I have the course precise enough for you!!

 

@EdBrazil and @OBI...great pics and diagrams. It's the little details that make a big project easier. Thank you.

[Skoot1123]

@jdk99 - Nice looking lake! Which direction is the lake situated? Good input from @OB1 as there are a few ways to "skin the cat." The one comment I like the best is to drop a portable in there and see which angle/direction makes the most sense from a wind perspective as well as from the Sun (if your facing east west especially). Whereabouts are you in the midwest?

[Chef23]

@jdk99 I don't have anything to add on the course issue but the lake looks fantastic.

[jdk99]

@OB1 ...30minute drive from Peoria International Airport. I think there's a Delta direct from Hartsfield. Doubt you'll be flyin' your 777 in here though!

 

@Skoot1123 ... Thanks. Located in Central Illinois. Top image is compass accurate. Lake runs SE to NW at about 300 heading. Largely perpendicular to summer predominant winds and enough northerly angulation to decrease late afternoon sun effect. Been looking for awhile and this came up ... couldnt resist. Great hunting (waterfowl and deer - Boone and Crockett taken last year) so I enticed my hunter friend to go in with me. Price about 1/5 of cost to dig our own. We honestly had no choice but to buy it!

 

@Chef23 ... Thank you, sincerely. We are thrilled with the purchase and it's nice to get confirmation from you all. You know you need a 12 step program when, outside the bedroom, it takes a burnt out strip mine lake in the middle of "Egypt" to get you excited!

[Edbrazil]

OK, another try with the Through-Ice article. This is just the Page 4 of a more general article.

[crashman]

Wow it looks like there are an amazing number of strip mines in the area west of Peoria. You'll probably going to need to have a baller gathering when you get it completed so we can test it out.

[6balls]

If I wasn't hosting records...I would throw in the highest quality portable in the business with some serious anchors and lots of tension, mid arm buoys to prevent sag, and perhaps river adapters both directions. At 30 ft deep bottom mount gives too much variance to surface. Side mount sounds like the bomb...but a lot more work.

 

Depends on what you want in there and intended purpose. Looks like a killer site!

[Edbrazil]

 

You probably can do the 20 crossline shore stake locations from one point, using a Total Station

survey instrument set up on the centerline. Looking at the original posting's pictures, it appears

that is possible. Likely use a boat to go up the shoreline at the left in the view. Initially, just mark

the points with fluoro flags on a piece of wire. Items you can buy at a local hardware, Home

Depot, Lowes, etc. Survey work would then be only a half day or so.

 

Then, plenty of time to drive the shore pipes (huff-puff) where the marks are, string the cross

lines and attach the buoys approximately, without having to pay a surveyor. Survey work will

be needed again. turning angles only, to get the buoys adjusted along the crosslines exactly.

 

FYI: Super-Tech Controller Dave Clark lives in Illinois.

 

[Skoot1123]

Depending on what you do for a cross course cable system, you can get a lot of bang for your buck at www.e-rigging.com Really great site.

[Edbrazil]

The e-rigging prices are relatively good. Maybe 50% more than what you might find at Lowes or

Home Depot, if you can find it there, such as SS eyebolts and quicklinks. Most of the other places

where you look for stainless hardware, prices are astronomical. Good find, thanks. For crossline

stainless cable, one good option is Mike Suyderhoud's Accufloat company. He will make SS cables

that are custom length, with swaged end hardware for fastening. Used that source for the 5 SL

courses at Miami.

Although, for starters, you could use all ski line for crosslines. You'll get some stretch after a

while that may require buoys to be re-sighted with an endcourse angle survey.

[jdk99]

Leaning towards the cross cable method. One of our locals suggested surveying and placing shore posts when frozen over then coming back to complete in spring. Anyone tried that?

 

Thanks for link @Skoot1123. Might I ask what method you used on your recently built lake?

[boarditup]

Another option is using street grating with swaged stainless steel cable loops though each opening in the grate. This will settle into the bottom with the cable loops sticking up. If you get the grate in close to the right place the additional loops allow for more attachment points for the sub-buoy. This does require a diver, but you have the advantage of a permanent anchored system that is really simple in the long run. Essentially it is a more flexable version of the poured block system already discussed.

 

I like the site. Not too far away from one of my wind farms....

[Skoot1123]

@jdk99 We actually have a crazy contraption to pull the course down for when we barefoot/wakeboard/tube. It would be pulled down by an electric winch - hopefully next summer. We used stainless cable and an anchor system to make it work. You can find it in one of the links on BOS. Our lake is only an average of 8ft deep though and it wasn't filled when we did the layout of the course. The ski club we were members at though uses cross course cables, albeit with nylon rope vs SST.

[Bongo]

Resurrecting a thread from the past, I wanted to give a shout out to Ed Brazil ( @Edbrazil ) for writing the article and re-posting it here for how to measuring and install a slalom course on ice. Also, various advice from this thread and others for what to consider when installing our permanent course; e.g. @eleeski‌ for the importance or lack-thereof for a turn island.

 

In our case, we've got about 2,100' of distance. One end with deeper water (12') and an 'L' shape, though inverted and the wrong way way for the slalom skier pull-out. The other end, somewhat shallow (4') and a straight pull into the course. Nonetheless, more than enough room for a Slalom course and separate Jump course.

 

The brief version of this past weekend's activities:

- Measure and mark slalom course.

- Re-measure slalom course.

- Consider impact to Jump course, especially where the Slalom 3-ball might interfere with the skiers approach to the Jump on a 3/4 cut.

- Slightly adjust slalom course. Really, only one turn-ball that was 5 cm off on the diagonal measurement (D for those looking at the official slalom course measurements).

- Cut holes, measure depth, assemble anchor lines and drop anchors into lake. (This went way faster than measuring.)

- Second-guess everything we just did.

- Measure and mark Jump course.

- Second-guess Jump course, especially if we've got enough room on the pull-out for big jumpers.

 

I've got a few anchors to drop for the Jump course, which I am confident will go quickly this upcoming weekend. Then wait for spring thaw and get skiers on the course.

 

Lake is at: 39°44'51.3"N 92°13'44.0"W

 

My co-owner and I have coined the name NEMO Ski Lake. Where NEMO might be:

(a.) cute little fish from some movie,

(b.) latin for nobody, as in nobody's ski lake,

(c.) Northeast Missouri, or

(d.) all of the above.

 

Great perspectives and advice on this forum that I considered when installing the temporary course and now our permanent courses.

[eleeski]

@Bongo Since you asked, it is very important not to have islands!

 

A drop buoy is helpful at the ends - especially where the dogleg goes the wrong way. That can wait until summer as the anchor isn't critical and you can set the buoy where it feels most comfortable for the skier and driver.

 

If you need to come out of the dogleg the wrong way for length, have a buoy on the boat guide line outside the 55s so that at least by the 55s you aren't working against the skier.

 

How does just 3 ball interfere with the jump? A Dr. Michaels style buoy sinker setup might help.

 

Cool name. But I won't come visit until the ice melts. Naturally Eager for the Melt Out.

 

Eric