The private lake I ski at has a floating course and I have been trying to convince the other members to put in a sited course. One member is concerned about the balls moving if a boat get caught and I have been getting a lot of other negative feedback as well!! Maintenance seems to be the biggest complaint. Since I started skiing comps a few years back I have come to really appreciate a sited/individually anchored course. I really want to convince them to do it but I need to know more about how to do it right!
1. How to build the anchors (Materials, config)
2. The best way to put it in? (Winter, summer, GPS)
3. Pro's and Cons of floating Vs. Sited?
Any help would be awesome as there isn't much info on this on the internet....
Here is a picture of the anchor I made for the 55meter pull out gates. Its 20"x20" and about 3" deep. I also installed two pieces of rebarb that stick out the bottom of the block about 3". We have a gravel base lake so I thought the rebarb would be a good idea.
My first question is how deep is the water?
Varies from 6-10 ft deep, maybe 12 at the most.
We have had a sited course in 30 to 35 feet of water for 18 years. No problems with movement. You definitely need heavy anchors. An easy anchor would be to find a chimney block and fill the middle with concrete and place an eye hook in the middle. As far as when to put it in, we did it on the ice in the winter (Massachusetts). I would highly recommend contacting Ed Brazil (firstname.lastname@example.org) or (603) 524-5756. Slalom course guru and all around good guy. He does this for a living and is very reasonable. You name the pro course he either installed it or worked on it. He and his assistant were the ones to discover Dr. Michael's secret.
Skidream, You are right about an individual anchored course. Thomas has given you a good place to see pictures of the already invented wheel and buy parts. The picture of the anchor that you posted could give problems when things start to rust. The rebar could become sharp as it rust and puncher body parts if you needed to make repairs after the chain rust and cuts your ropes. I think an improvement on skier to skier suggestion for anchors is to make them a little smaller, thinner and lighter. The PVC pipe should be at angles instead of vertical so the rebar will keep the blocks from lifting as well as shifting. I also suggest putting three stainless eyebolts to create a triangle for making final adjustments after driving the rebar in the ground. If you do not want to spend as much on the eyebolts, you can use four PVC elbows and six short pieces of pipe to make two “U”s per anchor or two elbows and four pieces of short pieces of pipe to make two “V”s for each anchor. If you go with the “V” shape you will need to fix the top edges as not to cut your ropes. By putting these crisscrosses in the concrete you will still be able to run your ropes through and make adjustments after driving the rebar down. If you don’t understand I will draw a picture and post it. Skier to skier has a good diagram for adjustable sub buoys and Thomas has a great drawing for self adjusting buoys. I have never met Thomas but he appears to be very intelligent based on many of his postings on the Web so do some searches on different forums for him. You can learn a lot from him. His drawing shows a three pound lead ball. I scratched my head to find something I already had to use. I came up with a section of PVC pipe with three pounds of gravel inside. Use a torch to heat and collapse the ends leaving a small gap to allow air to escape and drill one larger hole sideways in the flattened out top to attach your line up to the buoy. If you use your cable course as a template on dead calm days setting your sub buoys just under the eyebolts of your old course, you will be good to remove the old course and ski until you get your surveyor in. The whole thing is relatively inexpensive.
Last edited by BudMan (Sat, May 15, 2010 6:11 PM)
can you post a drawing of what you're talking about?
PS - I have planned to cut the rebarb off at the top of the blocks. Also after looking at skier to skier I will use eye bolts for the blocks here on out!
Skidream, See if this shows it.
To make your “pipe U” run rope through a piece of pipe about 30” long. Add rope stops and knot rope to keep it from sliding. This will give you four directions to pull the line that goes up to the sub-buoy.
Then warm the pipe with a torch, then bend it around something round (like a 5gal. bucket), then cool it to hold its shape. A pan of water will cool it instantly. Try to make it wide to reach the corners. It will give more adjustability. You may want to ease the top inside edges so the pipe want eventually cut the rope. Be careful not to collapse the pipe so you can replace the rope if needed. The picture shows light weight rope but you should use heaver to make sure it last.
Place two “pipe U” in each box before pouring concrete along with two vertical pieces of pipe angled to slide rebar through later. A good size and source for boxes is a paint store. One box split will make two anchors. Wrap tape around top to keep it from tearing. They will be about 13” x 13” x 4”.
Get the anchor close then drive rebar and then fine adjust with four corner ropes.
This is heavy enough to work with and then pin it to the bottom with rebar. The softer the bottom the longer the rebar needs to be.
The four ends will tie to the bottom of a double loop (8) of rope. The buoy line will come down to the top loop. Feel free to ask any further questions.
Our local club is on a river, in years past our cable course has had tough springs until the rain settles down here in the midwest and the current subsides. It's really never terrible, but we've been toying with the idea of installing an anchored course but being on the river we are faced with (2) main obstacles.
(1) obviously, current.
(2) this is the tricky one, the water is about 10-12 on east side, 4-6 on the west and the river runs from north to south. The main channel is the east bank, the deeper of the two. Our primary concern is with the individually anchor buoys, will the course skew as current and water levels fluctuate throughout the season?
-I'm digging the PVC sleave idea (by the way, a coil of PEX would likely be cheaper, just a thought)
-The finger trap line adjustment is genius
-any other suggestions?
I used the finger trap design of Skier to Skier. It works well, but do not use nails as weights. Used a piece of copper ground wire. You can get it from Lowes. Or insert a piece of lead fishing weight. Neither copper nor lead will rust.
PEX flexes then goes back and cost about twice what PVC cost even though it has a thinner wall.
As for the current, it would guess that it would wash out the dirt from under the anchors, but I don’t know.