Freediving...

There is nothing more pure, nothing more beautiful than freediving.  To truly become immersed in the ocean and connect with it, you have to strip yourself of the one thing that makes you comfortable on earth - breathing.  For as long as you are connected to oxygen you are disconnected to the world down below.  Add any marine animal to the mix, be it a dolphin, shark, grouper, or damselfish - and they too will immediately sense the disconnect...

Beyond the athletic aspect of freediving - the mental state takes each freediver to a place within themselves in which they find peace (which will vary for each) and calmness even when working (spearing / photographing / etc).

Freediving and having the privilege to interact with animals, no matter their size is something that cannot be replicated on SCUBA.  Of course that is some work that requires all the pesky gear --- but I would dare to say that a lot of it, particularly photography / videography can be done on your own breath.  Some of the best u/w photographers I know freedive only - some are old and some are young (there is no excuse).

With all the shark material that is being pumped out - there is nothing more beautiful than capturing a moment between sharks and freedivers (no direct interaction even necessary)...

And while you see guys getting more and more complex in what they do on SCUBA...in freediving you think about simplifying everything. 

Freediving with juvenile tiger shark and lemon shark.  Photo by Wolfgang Leander (freediving)

Freediving and filming tiger shark.  Photo by Raul Boesel (freediving)