About 35 minutes away from here is my favourite beach so far on the island, or in fact anywhere! Where we are in Réunion isn't really prime beach territory, by all accounts the west coast is where the best beach action is at. That's not to say that there aren't some nice beaches nearby, there are but swimming is generally limited to safe areas surrounded by rocks.
Then there is this black sand beach near the village of Vincendo.
Looking at the photos you'll see a steep slope in the beach. The slope means that incoming waves hit the slope and pile up really high and break just by the waters edge resulting in the BEST FUN EVER! Sam and I went there again today, he played in the surf (watched carefully of course) while I played in the giant waves, my oh my, am I going to ache tomorrow :).