Yes, red eared sliders (RES) can sleep out of water for short periods of time. However, they are not true terrestrial turtles and therefore cannot stay out of water for extended periods. They must have access to a shallow pool of water in which to soak and wet their skin as needed. If they are kept dry for too long, their skin will become cracked and irritated. In the wild, RES typically bask on logs or rocks near the water's edge in order to warm up and then return to the water to cool down and rehydrate.