When I was in the local water ski club, we used a system like that to anchor the ski jump in place. The only difference is that we made an "X" with the anchors on the bottom - we didn't run them straight up. Pully on the right had the cable running to the anchor that was under the pully on the left, pully on the left had the cable running to an anchor that was under the pully on the right. It worked very well. The problem that we had was not making the cables long enough for high water. The local rugrats would all climb on the jump, making it sink, then they'd all bail off. When it popped up, it would pop up high enough so it'd slightly yank on the anchors because the counterweights would slam into the bottom of the jump.
Due to those problems and concerns about liability we pulled it off the lake (public lake).
You know I was thinking of crossing the cables to but worried about the fish the kids catch off the dock wrapping them self around the cables. Just with the two on the corners may be allot as well to get wrapped around.
How well did the anchor system balance the jump for list and bounces?
I'm planning to build one very similar, only a little smaller, perhaps 12 x 16. In order to level the dock due to the weight of the gangway on the one side, I was thinking to add a couple of extra barrels on that side and add ballast (water) to level. Is that a reasonable approach or is there a better way?
You know after doing this I wish I had added some water to the barrels to lower my float height. I may have to add another barrel under the walk way too. I only have one under it. The whole dock is listing back to the walk way 3" on the 16 feet because of the weight of the walk. I really really under estimated the weight of the walk.
The other thought is to move the rear barrels back closer to the walk to help lift the rear of the dock. Because of the direction of the joist it only a few screws to move the barrel back if they are not wedged in there tight yet.
I bought a full lift of 2X6 for a total of 96 sticks. I then bought one 8 foot 6X6 for the 10" blocks in the corners and four good 16 foot 2X12 for the outer rim of main dock. All the barrels are set back 12" from the rim of the dock then evenly spaced joist between the barrels was about a 10" on center. All the joist are 2X6 with 2X6 bridging block rows on 4 foot centers. With the 2X12 16 footers they were 16 foot 3/4 of an inch long so I trimmed them to 16 foot 1/2 inch. My 2X6 were all 16 foot 1/4 inch so I did not need to cut anything just lay the deck boards in a screw them off. The ends are end screwed in through the 2X12. It is best to screw the full deck off before the sun get at the wood and warps it all before you get it screwed.
The walk way was 16 foot 3 inch long. I made it 64"s wide so I could get 3 planks out of each 16 foot 2X16. The long span of the 16 foot walk we put them on 10" centers and bridging blocking every 3 feet. I really should have placed two barrels under the walk because I have just about got that barrel totally under water and still have a list to her.
Cheers Don.
![[Linked Image from corvettejunkie.com]](http://www.corvettejunkie.com/pb.gif)
