Natural World: Superfish

The billfish are the biggest, fastest, and most dangerous gamefish in the sea. They have captured man's imagination like few other creatures, whether it's the graceful sailfish, the menacing swordfish, or queen of them all, the marlin, immortalized by Hemingway in The Old Man And The Sea. Marine biologist and filmmaker Rick Rosenthal has travelled three oceans in his attempt to capture them on film.