These three islands formed barrier reefs, one of the few of its kind in Indonesia. Pulau Besar is the largest island, followed by Dambilah and the Pangabatang. With this topography, it is no wonder the bay is primarily calm, attracting cetaceans like dolphins, sperm whales, pilot whales, and even whale sharks.
The coral slope in Pangabatang descends to 30 meters before forming a sandy plateau and entering the abyss. Aside from cetaceans, it is expected to see eagle rays, sea snakes, reef sharks, bumphead parrotfish, barracudas, trevallies, pipefish, scorpionfish, and turtles.