When Kurt Austin, the leader of a courageous National Underwater & Marine Agency exploration team, rescues beautiful marine archaeologist Nina Kirov off the coast of Morocco, he becomes the next target of Texas industrialist Don Halcon. A madman bent on carving a new nation out of the southwestern United States and Mexico, Halcon's scheme hinges on Nina's recent discovery involving Christopher Columbus, and a priceless pre-Columbian antiquity buried in the battered remains of the sunken Italian luxury liner Andrea Doria.