The waters around Trincomalee, Nilaveli, Pigeon Island and Hikkaduwa hold coral reefs, shipwrecks and a wide range of marine life, from reef fish to occasional turtle and reef shark sightings. Snorkelling trips suit all experience levels, while certified dive centres offer both introductory dives and courses for more experienced divers. However, conditions and visibility vary by coast and season; the east coast is calmest from May to September, and the south and west coasts are calmest from November to April. It’s one of the more accessible ways to experience the island’s marine biodiversity.