Oh, just swimming with the world's largest fish and snapping pics. No biggie.
If you think that, you might want to watch this video about just how difficult getting a worthwhile photograph of these huge creatures really is.
The Phoblographer makes an excellent point about it: "The creatures are already quite rarely seen in the wild and photographing one is tough. But beyond that, getting a compelling and publishable photo of one is even more mind boggling. Tom’s challenge was to document the creature doing something interesting and also get a sense of its enormous size in a single shot. While that may not sound too challenging to loads of photographers, consider the fact that you need to swim faster than the shark and while doing all of that you need to adjust your camera settings perfectly to get the right photo. That takes a major mastery of light and photography knowledge in general."
A big fat thank you goes out to all the photographers and filmmakers who go to such lengths to show us the wonderful planet on which we live.