The reef pass off Tiéti beach is the headline dive on the east coast. Outside the pass, the wall drops abruptly to deep water; inside, the lagoon flattens out over coral gardens. Currents through the pass bring in pelagic life — black-tip and grey reef sharks, schooling barracuda, occasional eagle rays, and turtles year-round.
Visibility is reliably good outside the wet season (roughly November–April), and the diving is straightforward enough for advanced open-water level divers. The Tiéti Hotel's small dive shop is the only operator on this stretch of coast; expect two-tank morning trips and the chance to do night dives over the inner reef. Snorkellers can join the boats and stick to the lagoon side.