Reply #11: I used to be in charge of cleaning the fish on vacation when I was a kid.

[JVS]

I would just cut off the head of the fish with one clean stroke. I did notice a mallet in the fish house, but I had been told that it was for the purpose of stunning the big fish who were thrashing too much to safely handle now. In retrospect, cutting of their heads probably didn't kill as humanely as would be possible. The heads tended to kind of keep moving at the mouth for a couple minutes. Fish are hard to kill quickly. I would recommend stomping down on it quickly with a hard soled boot if it's small and not to agitated in its flipping, or if putting it on the ground would cause it to thrash too much you could always pour it gently into the blender and the turn it on top speed suddenly. I know these sound like horribly gross methods, but the only way I can think of making sure that it wouldn't be feeling the kill is to obliterate the fish rapidly.