The film is based on a short novel by C.S. Forester (the author of the 'Hornblower' series of novels set in the 18th century) and entitled "Brown on Resolution". The film follows the story quite closely. Being a film made in the late 50s, it's full of stock British actors who can be seen in just about every British war film of the period (Bernard Lee, Victor Maddern, Patrick Barr, etc.)
At the time that this film was made, there were still numbers of British warships around that had survived the war and (rather as in the "Battle of the River Plate" film) were available for filming. In this case we have the 'Town' class cruiser HMS Glasgow and the 'Dido' class cruiser, HMS Cleopatra taking the part of the ships of the British cruiser squadron and the fast minelayer, HMS Manxman, dolled up as a German surface raider, with a rather obvious set of plywood turrets! Never mind, for the naval 'buff', this is priceless stuff.
It might be argued that some of the acting is a bit wooden, but that was the style of the time. This is a great tale of 'daring-do' and one which is hugely entertaining. Would that the modern 'blockbuster' could tell a tale so well and so simply without CGI! Buy it and enjoy it!