Underwater!

The scuba diver partners Dominic Quesada and Johnny Gray are treasure hunters that are seeking for sunken treasures in the Caribean waters. When they find evidences of the Seventeenth Century galleon Santo Bello in the bottom of the sea, they raise money and an adequate boat and they sail to the spot with Johnny's wife Theresa Gray, the boat's owner Gloria and Father Cannon, who is an archaeologist, to recover the treasure. The find the galleon located in a dangerous location on the edge of a cliff and they use a winch to try to hold it in position. Meanwhile they feel threatened by greedy shark hunters but they leave them in an island. When Theresa is trapped in the debris of the sunken vessel, Johnny and Dominic have difficulties to rescue her. But when they return to they vessel, they have a surprise.