Fished with my wife's father a few years ago in Pompano Beach Florida. We're in 400 feet of water on his 26 foot Glacier Bay Cat with twin Honda 4s. Not much happening until in the distance I see white water, we approach and the ocean is littered in in scales. turns out a shark is trying to kill a billfish and the fish is trying to leap free. The shark had several chunks out the bill's tail and he's not really swimming, more like thrashing around, sort of 'standing' up in the water. When we get real close the shark gets slightly spooked by our being there and gives the fish a few minutes alone. My father in law is going nuts, tells me to take the helm so he can gaff the billfish (don't ask). One swipe and he lands the gaff, but the shark is not happy and begins circling. The billfish is too heavy for him to heave over the transom so I join in and as we both give a heave ho the shark comes right up to the transom and swipes at the fish. I don't want to be a headline in the Miami Herald and question our (his) sanity. Father in Law is possessed, he wants this fish.= ( I told you not to ask!). I manage to get the fish onto the swim platform when the shark comes back at us, all jacked up obviously because it lunges at the portside motor and grabs a hold of the Dolefin. With a big shake we can feel that he's got the thing held tight. I cant take anymore of this and ask about his sanity, and I drop the fish, gaff and all. The billfish is trying to thrash its way from the lunatic humans and murderous shark, and we watch as the gaff, sunk deep begins to dance away from our hull. The shark makes one more turn towards the boat - as if to say "this is my last warning" - and again grabs a hold of the Dolefin. Unbelievable. I finally convince him to give up and head home, and we watch as the shark grabs a hold of the billfish one more time and takes it under water - gaff and all. We scooped up a few scales, wondered where our cameras were and headed home. Back at the dock we tilted the engines up and sure enough - teeth marks all over the Dolefin. We didn't have any lasing evidence other than that so we took that fin off and have it hanging in his garage now. I couldn't ID either the fish or shark, but estimate that the shark was at least half the lenght of the boat. Dad thinks it was a great white, but who knows. My first and last 'wild' shark experience.