I've seen it as well...known about the act of finning for quite some time...very tragic. I've always been at ease in the water with sharks (having lived and swam in the waters of FL, Panama (Central America) and HI), so I completely get where the film is coming from. I've only recently begun my diving adventures (wish I had done it sooner, but heck, don't we all!), and I am hoping and praying that I continue to enjoy shark encounters during my dives.
Of course the film makes the point of finning's hazards and pitfalls all too clearly, and retiterates the need for conservancy more than anything to ensure continued balance within the ecosystem in which we live. The film also portrays the beauty of the shark...the persistence of the shark's simple and effective design. It truly is a top-tier predator...without which, the seas will be in a horrible state of flux.
My Mom purchased the DVD first when it came out and watched it, and then called me crying...literally sobbing. She had no idea!
Hopefully, Rob's film will make the mark on people's psyches that it should...the problem is, there are too many more people with that indelible memory of their first viewing of "Jaws" to care about a documentary film with infinitely more accolades, as have been bestowed on "Sharkwater."