旗鱼在供人捕钓的食用鱼中，体型最大、速度最快而且价值最高，这种鱼以其呈枪矛状或剑状的吻骨延伸而闻名，马林鱼、剑旗鱼和枪鱼都是旗鱼的一种。从哥斯大黎加外海的海底峡谷，到大堡礁的热带海洋，本节目穿梭在全球某些最美丽的海底世界之间，寻找一种重1千磅、长15尺，行踪飘忽的马林鱼。沿途我们也遇到了一些最迷人的海洋生物：大群海豚、鲔鱼、罕见鲸鱼、鲨鱼和海龟。

The billfish are the biggest, fastest, and most dangerous gamefish in the sea. All 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 film-maker Rick Rosenthal has travelled three oceans in his attempt to capture them all on film, and in doing so has become a passionate champion for these endangered yet little-known ocean giants.