Sahara (2005)

Retired US admiral Sandecker's foundation finances various projects worldwide, including high tech marine salvage by brilliant Dirk Pitt's US Navy Seal veterans team including buddy Al Giordino, which dreams of finding the mysteriously missing Confederate gold aboard the ironclad battleship 'Ship of Death'.

Pitts bumps into evidence for his theory it crossed the Atlantic up the river Niger, where the admiral has an environmental project. Alas, it's a West African dictatorship where the ruthless president suppresses the desert people, in league with billionaire French energy industrialist Yves Massarde. Saving reckless WHO epidemics researcher Dr. Eva Rojas, he learns the secret: tribal slaves run a waste plant whose toxic output threatens, through an underground fluvial system, to pollute the ocean and hence cause a global killer epidemic.