I was told that the corals in the region are not in very good conditions because of the fishing activities. Dynamite has been used to fish here. Almost all corals have been destroyed. I was told that in some of the islands you still have good sites to dive. If you are interested in scuba diving, make sure you are brought to a nice place. I do not consider Nha Trang a place for advanced scuba divers, though. It is more a place to take the courses.