Goldie Oldie British flick from 1956. A docudrama about the sinking of the Graf Spee at the beginning of WWII. From the Rank people, whose opening trademark was a giant brass gong being struck with a mallet in the hands of a beefy guy with his shirt off. It's in Techicolor and Vistavision (wide screen process like Cinemascope). It came from Netflix. A period piece from the era of good WWII British war movies.
They used real ships, including one survivor of the 1939 battle, so the sea scenes are good, not model work. The real thing, was treated as a tremendous victory by the British, who were yearning for some good news after a disastrous string of German victories. Graf Spee was an extremely heavy German cruiser armed with 11 inch guns, far more powerful that the 6 or 8 inch armament of contemporary cruisers. The British, remembering the damage done to them by ultra heavy American frigates in the War of 1812. In that war much weaker British frigates felt honor bound to engage the Americans, who promptly used their heavier guns and bigger ships to blow the Brits out of the water. To prevent this sort of foolishness, the Brits dubbed Graf Spee a "pocket battleship", which enabled British cruiser captains to put up their helm and run for it, rather than getting sunk engaging a much stronger vessel.
Three British cruisers caught up with Graf Spee off South America and closed for a furious gun battle. None of the ships carried enough armor to keep out the enemy's shells and all ships took quite a bit of damage. Graf Spee broke off the action and took refuge in Montevideo harbor in neutral Uruguay. International law forbade neutrals to harbor belligerent warships and so after a couple of days Graf Spee weighed anchor and came out to face the British. Only she scuttled, blew herself up, rather than engage the three battered British cruisers lying in wait for here off Montevideo. The British treated their victory as the sinking of battleship rather than a mere cruiser.
The movie treatment of the Germans is sympathetic. But they omit a scene where German skipper Langsdorf gets a chance to explain why he decided to scuttle instead of fight. They do have scene where the British officers speculate on what Langsdorf might do, they all think Langsdorf will come out and fight. The action scenes could have been better. For a sea fight we want to see the guns firing, and then we want to see whether they hit or missed. The director didn't bother, we see the ships closing, but it is unclear who is hitting and who is missing.
Anyhow, it's a good sea flick, enjoyable as a period piece.