I help maintain a public course where I ski and our recipe has been Schedule 20 pvc rather than Schedule 40 to allow for a little more flex from big waves, changing water conditions, fisherman - and we've had alot less breakage, almost zero actually...  We run 6ft HD bungees on all boat guides and buoys to keep our mainline and pvc well below prop level of even large boats.  And I suppose it helps that our course in tucked on a shoreline in the very back of a cove...  Maybe its just my perception but I feel like we've gone through less buoys and boat guides in recent years but on average I'd say we only have to replace one buoy or one boat guide every few weeks.

Our mainline is a steel cable mainline, i'd say its every bit of 12 years old but it still looks brand new once you clean the algae off of it...  Call Ed at EZ-Slalom and he can give you a ton of information regarding course maintenance and best practices.  His number is on his website ez-slalom.com

I had a course in a popular cove in a public lake back around 20 years ago. As long as we had horizon structure under water, fisherman would get their hooks caught, get mad and cut up stuff. I went to individual blocks then drove 5’ rebar through at apposing angles to keep them from pulling up. Then ran ropes up to sub buoys about 6’ under surface. Thin bungee from sub-buoy to white plastic floating shower curtain rings for turns to be removed when not using. All members have their own 6 turn buoys. All lane buoys attached with zip tie to thin bungee. I then leased a private lake, only club members. Occasional beaver problem thorough. They would sometimes separate the buoy from the solid rubber eyelet with out letting the air out. Those weren’t bad. It was frustrating when they chewed the rope off of the anchors in the winter. That required diving to repair. I have now built a lake and just hope the good Lord continues to bless us with water and good health.

I really like the shower ring idea. That is a great and fast to pull and install. Does using the long round boat guides help for streangth compared to using balls? Bud, I hope your not having problems on your lake there. I will be going to my Charlotte office here in a couple few weeks. Would it be ok to give you a shout?