In both world wars the Admiralty pursued a policy of arming fast merchant ships with various old guns and using them as ocean boarding vessels and convoy escorts. These were called Armed Merchant Cruisers (AMCs) but the sailors soon dubbed them Admiralty Made Coffins.
Inevitably there were tragedies and two of these were HMS Rawalpindi and HMS Jervis Bay. The first ran into KM Scharnhorst and KM Gneisenau, the second ran into the KM Admiral Scheer. Both ships' captains chose to turn and fight, the Jervis Bay in defence of a large and valuable convoy. The Germans wasted so much time sinking her that most of the convoy escaped into the deepening darkness of sunset.
There is a new film from Oceanliner Designs here: YouTube link
I follow him on YouTube on merchant shipping and liner subjects and find him interesting and informative. Oddly he missed out the whole saga of the MV San Demetrio. This latter ship was an oil tanker set ablaze by the Scheer during the same attack and left burning. The crew separated into two groups. One half was soon picked up and they presumed the San Demetrio had sunk but the other half drifted for a day or two before sighting the burning San Demetrio and managed to re-board it and put out the remaining flames.
Using only a schoolboy atlas they managed to navigate the ship and most of its cargo back to Britain and were even awarded salvage money for their efforts:
link
Barry
looks at another D-Day: German set for Flames of War.
