Phi Phi is one of the best dive bases in the Andaman Sea. The dive sites around the islands include strong walls at Ko Phi Phi Leh, the famous Shark Point and Anemone Reef to the south, and the King Cruiser wreck. Dive shops in Tonsai Village run full PADI courses from beginner to divemaster, and day trips can include two or three dives at multiple sites.
Snorkelling is just as rewarding for non-divers. The water around Bamboo Island, the western coast of Phi Phi Don, and the shallower parts of the Phi Phi Leh circuit all have healthy reef sections with good visibility. Most boat tours from the pier include snorkelling gear in the price. The sea is at its clearest from November to April, though diving is possible year-round.