Brad and Tony work as rescue divers on the Caribbean island of Jamaica. One day they are hired by Dwight Trevor to find the ship The Lady Luck. It is believed to have sunk with all its passengers and a million dollars worth of gold bullion. Although there is no trace of the ship, there is a sunken city called Port Royal that was destroyed by an earthquake in 1692. In fact, one million US dollars worth of gold bars were lost in a recent earthquake, part of an insurance scam orchestrated by Trevor. Trevor does everything he can to prevent the divers from finding the gold and will stop at nothing to make sure his plan works.