Founded in 1973, Poseidon Diving Station is Sri Lanka's longest-running dive operation and the country's first PADI 5 Star Instructor Development Center. It runs two bases, Hikkaduwa on the south coast and Trincomalee on the east coast, which lets guests keep diving year-round by following the seasons across the island.

Wreck diving is the specialty, alongside reef exploration, night dives and the full PADI course range up to instructor development. Teaching runs in English, German and Sinhala with a highly experienced local team. The operation holds a 4.5 rating from more than 460 reviews.