Where and how do crocodile's sleep?

Crocodiles normally sleep very lightly, and can fall asleep and wake up repeatedly during the day - they actually seem to sleep less at night. They do this where they spend most of their time, in or near bodies of water. When I was a student I kept small alligators, which of course are closely related to crocodiles, and I remember that it was difficult to catch them sleeping because a slight noise or disturbance seemed to be enough to wake them up.