Here's a lovely under-the-sea exploration toy I found in the Ludum Dare 34 Pile O' Things. It's called From The Sea, Freedom [official site] and it made me crack a smile even though I was in the mood to chuck my PC in the bin on account of wrestling with a free camera thing in Dota all morning and then failing anyway.
Developers, SecondDimension, have put you in charge of guiding a little diver around an underwater scene. Curious-looking holes on rocks represent places where coral will spring forth if you go over. As you interact with the environment and cause more corals and plants to appear you'll also attract more fish.
A text box at the bottom of the screen sometimes pops up to let you know you've discovered a new creature or plant or object. I think some are related to what you can see but others seem to be more about things you might have seen while swimming about, or that the diver is discovering and letting you know. A stoic crayfish was one which just popped up for me and I'm not sure if it meant the crayfish-ish creature a few game feet away from the diver or whether he was peeking inside the shipwreck on the seabed behind him and telling me what he could see. It's also possible that the triggering system is inexact or needs a bit of work but if that's the case I think they should keep it as it is because the ambiguity is charming and encouraged me to imagine more about the little world.
I think I'll bookmark this for when I inevitably try to do the Dota thing again.