Wallaroo, South Australia.

The black circular thing is part of a swimming net (you're looking at the floats) to keep shark of of a swimming area.

It's difficult to get good tradespeople these days and not just plumbers. I thought I had a good one, he was good up until now, but he's let me down now, a few times, and I'm moving on. We have to rely on the advice others give us if they're the "professional" only many of them don't act professionally these days.