Action in the North Atlantic (1943; also called Heroes Without Uniforms) is a black-and-white war film starring Humphrey Bogart and Raymond Massey and directed by Lloyd Bacon. It's about sailors in the U.S. Merchant Marine who are transporting fuel, supplies, and weapons across the Atlantic during World War II. Typical of films shot during the war, it has elements of propaganda and seems to have partly been created to boost the morale of the American public.
The best parts, unsurprisingly, are the action scenes, from escaping burning ships to barging into U-boats, to sea battles with German warplanes. Bogart's and Raymond Massey's performances are great, Bogie with the same cool, hardened exterior that many of his other characters have. Though with so many actors in this one, and the action sequences themselves, he's less of the main focus.
There's a great bit when their ship comes into port in Nova Scotia for cargo before setting off for Russia. All around are ships representing the allies, including Australia, Mexico, China, Russia, Cuba, France, Canada, Italy and a few more, and their crews greet them in their respective languages with bonhomie and flags flying proudly. "That's something you've never seen in your thirty years at sea," says Bogart as he gazes out at the fleet.