Koh Chang has developed into a major dive destination in Thailand. There are excellent diving opportunities in Koh Chang marine National Park with many dives ranging from Coral pinnacles, to deep wrecks and shallow coral reefs.
Visibility is often up to 30 or 40 meters in high season. Diving is best between October and May when the seas are usually calm and the visibility good. Popular sites include seamounts to the west of Koh Chang and other deeper diving sites can be found further to the south.