"Sleeping is a kind of refuge," Shelley added. "There's psychological pressure here being in this thing so when you get to sleep it's easy to stay there."
Both men say they knew going in that life on the wheel would be tough, and they are trying to stay mentally tough until they can get back on terra firma.
"Ten days is a number you can hold in your mind and count down," Shelley said. "It's like being told to stand in the corner when you're a kid."
Associated Press videojournalist Bonny Ghosh contributed to this report.