Its cool coming across scenes like this. A few years ago I saw some action a mile out or so, with the gulls in a frenzy over the water. I motored over and found a school of pilchards (small sardine size baitfish) being herded by a school of (Australian) salmon, which were being taken by a couple great white sharks.
It was such a feeding frenzy, that when I cast a lure, it was instantly taken by a salmon, sometimes before it hit the water.
Lots of fun.