Wayyyy back when I was a lineman, I could get 1/4" galvanized support strand for free.
And PVC pipe from a wholesaler friend. I also had industry pricing for preformed galvanized grips and splices.
If you have a fairly long and wide driveway, it's pretty easy to build one and by incorporating a little extra sag length between buoys - absolutely accurate. They were heavier than the ones using smaller lighter cables, but at 6,000 lbs tensile strength, breaking wasn't even a thought.
So, I built 10, maybe 12 accufloat type courses and put them in all over SW MI lakes.
Yes, about 15 years later the galvanized steel did rust where the galvanizing was scraped off from the diamonds.
Best result was meeting a lot of skiers, growing the sport and having multiple sites to shred!