Very impressive moment well taken, enjoyed it, great shot.
Your Whites in the photo are nicely under control a thing i love about my D3X, i have never had a bad photo using that camera, its brought me so much joy, and with my 70-200 FL and 300 2.8 is flawless. It delivers natural or organic looking real photos. Amazing camera.
Its sad to see the shark decline in your area, any known reason, has the food chain moved or declined also.
Huge floating fishing trawlers/factory's have in the past just harvested the ocean and kept everything they netted, sharks dolphins etc, then smaller trawlers from north of Australia had been arrested with hulls full of just thousands of shark fins but no sharks, the bodies were discarded once the fins were removed.
We have seen warmer tropical weather moving progressively further south, our seal population according to fisherman have also moved further south.
We have seen more lone sharks in the swimming beaches than ever before.
We used to have sharks move south down the east coast from up north in massive schools of 500-600 - 1000 plus at a time, now no more.
I don't know what the answer is other than we are seeing lots of change.
Keep enjoying your D3X, i do.
Only an opinion