Things not to do.....

The frst rule of underwater photography is get close then get closer. The closer you are to your subject the less water, and items in the water there are between you and the subject and the better the image will be......generally.

Here's a picture of the author (when younger and stupider) with an uncooperative subject. I'd already got a couple of nice shots of this girl when my buddy suggest he take one of me hovering alongside her. This was a step too far so she exited stage left at high speed.

and here she is prior to take off.

A wobbegong shark a little bit bigger than me. Some things are not meant to be got too close to. Wobbegongs are one of those things. After she swam a few yards she resettled and we left her alone whilst I restarted my heart.