We have a floating course at our site. We use the same bungee method as TW has illustrated above (works great!). Our site has a lot of wakeboard traffic passing thru and also boarding there when there aren't any skiers to claim the site. To eliminate pvc breakage on the arms, they put 6" sch 80 pipe sections (kind of expensive, but durable and no flex), although they get broken periodically. On one private site i've skied, they use 2" pvc that has been placed vertically into a concrete block, then surveyed into place prior to filling the lake. Then they made up some 10-12"x 1.5" brass weights that slide up and down in the pvc tubes. So if a rope hooks a buoy, the brass weight comes out of the pvc pipe. Then all you have to do is find the location of the pipe and drop the weight back into the pipe and you're back in business! At another private site, we made up concrete anchors using stainless eyebolts, surveyed prior to filling the lake, then used a section of 1/8" stainless wire rope, added a 2" chunk of the hard foam cylinder boat guides as a sub buoy (placed below prop level), then attached a drop line with a brass hook and a sliding tent rope adjuster so the buoy level can easily be adjusted according to water level. This system worked real well also!