We were camping at Ganzekraal this weekend (about 30km up the west coast from Melkbosstrand outside Cape Town)
Saturday and Sunday in the morning a number of small planes went over from Cape Town north towards Langebaan, some of them really close to shore or even right over the camp sites, and really very low, and a number from Langebaan traveling south towards Cape Town in the afternoon.
The two planes flying the lowest were the same two flying north and then later south.
I had the drone up later, and stayed very low (20m and lower) but climbed to 50m once and in my estimation that was higher or very close to the altitude of the two planes (I could be wrong, it is very subjective).
The challenge was that the planes flying higher could be heard much sooner, while the two low flying planes I could only hear once they were very close (campsite is right on the beach/rocks with quite a lot of wave noise).
Really made me nervous to fly higher, but then again the best photos and footage I have is always low anyway.
No, I have no photos of the planes, was not flying at the time.