"By the mid-21st Century, humankind has colonized the oceans and formed the UEO--the United Earth Oceans--as a military organization to police it. Formerly a high-ranking member of the UEO, Nathan Bridger (Roy Scheider) retired after the death of his wife, and retreated to an isolated island to study dolphins. An attempt is made to hijack the Seaquest DSV, the UEO's most powerful undersea vessel, and Nathan--its original designer--is convinced to return to active service, to assume command of it."