Carter Manning, a marine biologist and mechanical/electrical engineer, was vacationing with his wife on their private yacht when they found themselves under attack by 21st century pirates. Hopelessly outnumbered and outgunned, Manning's wife was killed and he was tossed overboard to the sharks. The pirates used his boat for a multi-million dollar drug run, and then abandoned it. Manning survived. Due to an amazing stroke of luck, he was rescued and returned home with the aid of the authorities. Manning mourned his wife, then entered his workshop and began design of the tools of his vengeance. When the same pirates attempted to storm yet another ship, Manta Man intervened and rounded up the criminals with little difficulty.
Manning decided, at that point, the he would new dedicate his life to the cause of justice.