Knysna gets rain all year, and the forest that comes with it is the biggest obstacle to a good signal. The dish points north-east, low over the hills, so a tree or a ridge on that side of the house can block it completely. On steep plots in Paradise and Hunters Home the roof is often in the shade of the slope, and the dish has to go higher or further along the house to see past it.
We check the line of sight with a signal meter before we drill anything. If the roof cannot see the satellite, we use a pole, a wall bracket on a gable or an outbuilding with a longer cable run. A dish aligned by eye might work on a clear day here and then fail in the first heavy shower.
The lagoon keeps the air damp, and close to The Heads and on the islands it is salty too. Every outdoor fitting we use in Knysna is galvanised or stainless, and every outdoor connector is a sealed compression fitting.