I came across the Polish submarine Orzel indirectly on Facebook. It was mentioned in a post about a British sub wreck, HMS Narwhal – https://en.wikipedia.org/wiki/HMS_Narwhal_(N45), that was found while looking for the Orzel: Found 77 years on.. icy tomb of british submarine with 58 seamen on board: https://www.youtube.com/watch?v=rv3MsRBDdu0&t=4s (around 3:19 minutes long)
I didn’t think much about it at the time, but a few days later, I came across another YouTube video, this one by The History Guy: The Extraordinary Voyage of the Polish Submarine Orzeł: https://www.youtube.com/watch?v=361AL2pJkmQ (about 12:36 minutes long).
It’s an unusual tale. One of the most interesting parts was how she escaped from Poland when Germany invaded in 1939. The sub made it to Tallinn, Estonia for repairs where the sub was almost impounded by the Estonian government. The sub was able to slip away and make it to Great Britain where the crew and sub would serve until they were lost. The sub was lost sometime between 23 May and 02 June 1940.
YouTube (search): https://www.youtube.com/results?search_query=orzel+submarine
Estonian Maritime Museum http://meremuuseum.ee/en/ has a plaque – https://en.wikipedia.org/wiki/ORP_Orze%C5%82_(1938)#/media/File:Tallinn_orzel.jpg in both Polish and Estonian detailing the “Orzel Incident.” You can see the plaque