It is the Indian ocean.
The flight path between Perth and Johannesburg typically follows a southwest trajectory across the Indian Ocean, crossing over parts of Australia and then heading towards southern Africa. Flights often take a route that passes near or over the southern coast of Africa, depending on air traffic and weather conditions. The distance is approximately 5,600 kilometers (about 3,480 miles), and direct flights usually take around 10 to 11 hours.
Travelling from Melbourne to Perth via the Great Ocean Road and Esperance is a distance of 3906 kilometres. Actual travelling time is 48 hours, but this does not allow for rest stops. It is a trip best spread out over an absolute minimum of 5-6 days.
When traveling from Perth, Australia, to Durban, South Africa, you cross the Indian Ocean. This body of water lies between the eastern coast of Africa and the western coast of Australia, serving as a major route for maritime travel between the two continents. The journey typically involves a significant distance over the ocean, connecting the southern hemisphere regions.
Clouds would usually be more common over an ocean.
there would be no ocean anymore.
North Atlantic Ocean
Air over the ocean would have more moisture than air over a desert.
If you go to travelocity, it will tell you that from Vancouver to Johannesburg, there is a stop-over in Hong-Kong.
The Pacific Ocean.
Over there ----->
A flight from Amsterdam to Johannesburg will fly over Belgium, much of France, the Mediterranean Sea, much of Saharan Africa, Nigeria, the Gulf of Guinea, Angola, Namibia, and northern South Africa before descending into Johannesburg.
There is not always a stop-over on London to Perth flights. It depends on which airline you use. However, stop-over flights typically are less expensive.