Nusa Penida

Manta ray encounters at Manta Point occur year-round with 95% sighting success from June to October, drawing 500,000 annual snorkelers. The island's rugged landscape features 40 km of coastal trails linking hidden lagoons like Angel's Billabong, which is 50% less crowded than Bali's main beaches. This raw, untamed island rocks the strongest marine biodiversity on the list, with 200+ coral species recorded in its waters.