A. they both go crazy for jelly
I posted a pic a while back of the back of a green turtle with her head in a jellyfish with the promise of the full story to follow so here goes. I found the turtle picking at a dead jellyfish on a reef wall but she shot straight off as I approached. On a whim I decided to hang around in case she'd gone to the surface for a breath (turtles of course being air breathing reptiles). 5 minutes later I was just feeling a bit silly and my buddy was looking impatient when she came rocketing past us back to the jelly.
Soon she was so engrossed in her lunch it was over her head and she was bumping into the reef and indeed us.
allowing us to get very, very close and allowing me to take my favourite turtle picture ever: