I came across this turtle taking a nap one day while I was out snorkeling.
From the surface of the water I could see a small cave about 12 feet down so I took a deep breath and swam down to take a peek inside. I was surprised to find the honu (Hawaiian green sea turtle) laying on the sandy bottom getting some rest. He was all the way to the back, apparently so some idiot tourist like myself wouldn't bother him.
I snapped a few photos and then headed back to the surface to get some air. I found a couple of small caves like this in the same area and they both had turtles resting in them. I will definitely be going back!