The main beach in Positano. It is pretty much divided in 4 areas - paid beach club, only residents and 2 public areas that anyone can access.
The public areas are located on the extremes ends of the beach, residents and beach club centre.
In the public area you don't need to pay anything and any corner will do. As we knew we would be travelling around the Italian coast, we brought beach towels with us and our Airbnb provided a beach umbrella (small but enough to us to hide from the 38oC summer day).
If you plan to travel around the coast, buy a beach umbrella at any store (about $12 Euros). As the paid beach club charge around 15 Euros a day each beach chair with umbrella.
Spiaggia Grande is not sand, but rocks and during hot days the hot rocks will burn your feet. So wear flip-flops. Everyone walked to the water in flip-flops then left it near the water.