Most dive shops lead whale-watching tours between July and October when humpbacks swim near the coast. Scubananas – Réunion Plongée has good credentials.
The dive spots off Pointe au Sel to the south of St-Leu offer some of the best underwater landscapes in Réunion, while the lagoon closer to St-Leu is good for coral.
St-Leu is one of the world's top spots for paragliding, with excellent uplifting thermals year-round. If you're new to dangling yourself in the air, you can tandem paraglide with one of the many operators offering flights. The most popular launch pad is at an altitude of 800m, high above the town. There's another launch pad at 1500m. The descent from the mountain is amazing, with heart-stopping views over the lagoon and the coast. Children over six are welcome.
The surfing scene has almost vanished, following several shark attacks that occurred off Boucan Canot, Pointe des Trois Bassins and St-Gilles-les-Bains. It's wise to seek local advice before hitting the waves.