I was discussing this with a podiatrist (who lives in Hopeman) I visited later, and she said that some days the turbines are easily seen, but other times, even with excellent visibility, simply cannot be seen. I suspect that was as strong mirage effect today. Air temperature was +1C and water temperature +9°C.
Photo details: 1,200 mm lens (equivalent) - a very long telephoto. Image then cropped to illustrate.
Fata Morgana perhaps?