Sunken Island is so called because it literally is a sunken island. Or more commonly known as an underwater pinnacle. The Pinnacle is located near the middle of the Tanon straight, marked only by a mooring line. The top of the pinnacle starts at around 23m, with a diameter of only about 12m, before the sides of the pinnacle disappear into the abyss. This is an unsual dive site, you start the dive by descending hand over hand down the mooring line, after a few metres descent you start to see a large number of small sardine like fish swimming above the pinnacle. A few more metres and you start to see the top of the pinnacle emerging from the blue. Shortly after you touch down on the top of the pinnacle itself. Surprisingly there is some marine life down here and it is nice to explore the pinnacle. The main interest is the abundance of pelagic fish, but mostly the way the fish behave. They are extremely on edge in this area, a quick movement of the dive torch can send the fish darting in 50 different directions at once. That feeling everything is on edge at sunken island gives you the feeling big predators are around and they are. Though you do need to be lucky to see them. Many divers visiting Moalboal request to visit sunken island when they hear about it. However dive centres in Moalboal rarley make trips there, the currents can be strong and both upcurrents and down currents are present. Coupled with the depth only Advanced divers with many dives should attempt this dive.