Our favorite beach to visit while in St. Tropez was the Plage de Pampelonne. This beach is about 5km long. It alternated between beach clubs, where you could rent chairs and umbrella and open beach, where you can set up your own blanket, chairs & umbrella.
The water wasn’t too chilly, more refreshing because of the heat and clear. We wore our goggles and could see clearly in the water and a few fish! The water is also fairly calm and not many waves.
The most interesting part of visiting this beach is to watch all the yachts come into the area. They would anchor and then a dinghy from one of the beach clubs would fetch the people from the yacht to spend some time at the beach. Or they would unload their jet skis or other toys from the yacht and play in the water.
We saw a really cool water toy that I called the Water Rocketeer. It is actually called Flyboard. A tube is attached from the Jet Ski to what looks like a shortened snowboard. It somehow generates the propulsion necessary to allow someone to fly above the water and then do a bunch of tricks, like diving into the water and immediately flying back up and flips.