I like the composition in the first one, but wish the batfish was in the left hand third, swimming into the shot, instead of out of it (yeah, picky, I know). BTW, like the lighting on the batfish.
The sweepers and wobbegong is great ... exotic subject plus activity, good exposure.
Manta shot ... the one on the left is at a real odd angle ... kind of ungainly ... otherwise I like it.
Anemone ... just excellent composition. If only it could have been lit a bit more, and had some punchy color in it. Yeah, picky again ... a real nice shot!
My votes? They're all great ... the second shot, then toss-up between first and last.
Good luck!