A black and silver missile appeared below us, head down, a wild whip of a tail, longer than its body, undulating in the electric blue water. "Thresher shark!" somebody said. I had seen smaller ones, never realized they attained such monstrous size. The long, impossibly graceful tail broke the surface, and my buddy the first mate struck the fish with the flying gaff, somewhere in the gills. All hell broke loose. The thresher exploded from the water, and then tried to sound. The rope I was supposed to be holding tore the cleat cleanly from the fiberglass of the gunwale, as the boat rocked mightily. But the mainline held, and the spool began unwinding again, though the huge fish was swimming only a foot or so under the water. Our captain, a man only a couple years older than we were, emerged from the wheelhouse holding the boat's .223 Ruger Ranch rifle, and cursing, pumped a half dozen rounds, fast, into the shark's head. I'll never forget the deep thudding sound of the bullets striking, or the explosion of blood into the water around the fish.