An underwater cave is a large cavern located at the bottom of the ocean in the diving areas of The Sims 3: Island Paradise. The underwater cave is one of the things a Sim can interact with while scuba diving. Sims can explore an underwater cave from 60 to 90 minutes, and while exploring the cave, there is a 45% to 95% chance of finding something, depending on the Scuba Diving skill. It could be some metal, a gem, a shell, a message in a bottle, a magic gnome, or a scuba magic gnome. When exploring, there is also a 35% chance of finding an air pocket inside the cave.