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 that it sank with all passengers and gold bars worth one million US dollars. Although there is no trace of the ship, there is a sunken city called Port Royal, which was destroyed by an earthquake in 1692. In fact, a recent earthquake has lost $1 million worth of gold bars, which are part of an insurance fraud that Trevor orchestrated. Trevor does everything he can to prevent the divers from finding the gold and will stop at nothing to make sure his plan works. A captivating adventure full of excitement, action and impressive underwater shots. Filmed in exotic locations and starring Anthony Quinn, Robert Ryan and Mala Powers.