Adan Shimo, off uninhabited Akenashiki Island in the Keramas, is a 10-minute boat ride from Aka Island. With mild currents, 7–20m depths, and clear waters, it’s perfect for both beginners and training dives. Expect coral gardens, clownfish, spiny dogfish, goatfish, and nudibranchs like Adeyakami and Fujinami.