On the Beach (1959)

Set in the year 1964, a catastrophic atomic war devastates the population in the northern hemisphere, leaving only one American submarine seeking refuge in Australia. Amidst a facade of normalcy concealing underlying despair, American Captain Towers grapples with the tragic loss of his wife and children during the apocalypse, while crossing paths with the weary yet captivating Moira Davidson. As a bond begins to form between them, the submarine embarks on a reconnaissance mission shortly before an impending end. Will Towers and Moira discover solace in each other's company amidst the impending doom?