Well, he really isn't sleeping, more like recharging...they come up from the depths to warm up and get some sunshine. This guy was hanging out at Kau's Punaluu beach...very cool place to enjoy the "Big Blue".
The sea turtles are always a awesome sight...I have been snorkeling and had one come up on my side and gently bump me (a little nerve wracking when you are out in the water with your face down!), I backed away (you aren't supposed to touch them or even be close to them because they can get diseases from us...) and he scooted right in front of me to start munching the algea on a rock I was in front of! Guess I was holding up the line to the salad bar! ;)