You can see things under the sea. See?

Honu (turtle) under the sea

Taken in a little over 60 feet of water (a hair under 20 meters). At this depth reds, oranges and yellows are mostly gone from the light – you’re stuck with mostly blues and greens (unless you introduce your own light).   This was taken at a deliberately sunken boat (to make a reef). Turtles like to gather here & hang out on the roof of the boat, where surgeonfish (in the background) pick algae off of them.

For this shot: I’m maybe two feet away, with the camera on wide-angle. He didn’t even twitch – no fear of divers. I ultimately got within 6 inches of the guy, but then left (and left him alone)