Ever since humans first took to the seas thousands of years ago, sailors have faced numerous dangers. Ancient civilizations tried to explain these dangerous conditions by claiming that they were the work of angry gods or monsters. While scientific explanations have been advanced for dangerous phenomena such as high waves, hurricanes, and treacherous ocean currents (steady flows of water in a prevailing direction), many lives are still lost in the water each year, mainly due to drowning or hypothermia. Hypothermia is a condition where the core body temperature becomes too cold to function properly. Prolonged exposure to waters that may initially seem warm, between 70°–80°F (21°–27° C), can cause death from hypothermia.

Whirlpools

Some of the earliest written works make references to the dangers of the seas. In the Odyssey, Greek poet Homer mentions a great whirlpool that a group of Greek warriors encountered on their return...