Gray Lady Down (1978)

In the unforgiving depths off Connecticut's coast, the nuclear submarine USS Neptune lies crippled, a victim of a catastrophic collision with a Norwegian freighter. Time is of the essence. A perilous rescue operation becomes the Navy's only recourse, a desperate gamble against crushing pressure and dwindling oxygen. The stakes are impossibly high: the lives of the Neptune's crew hang precariously in the balance, suspended between hope and the cold, dark reality of the ocean floor. Can they be saved before it's too late?