Well I found and watched Greyhound. Historically it was rubbish, with shades of stolen valour. Most of the Atlantic convoy escorts were British or Commonwealth corvettes or such which must have been hell in bad weather. Fletcher Class destroyers [best of class at the time] seldom roamed the Atlantic.
There is a mini series on FoxTel, The War Gamers, which tells a little of the real story. If a reader try Nicholas Monsarrat's novel The Cruel Sea. I read it as a young man and never felt like reading it again.
A search says it was made into a film.
1953 film by Charles Frend
The Cruel Sea is a 1953 British war film based on the best-selling 1951 novel of the same name by former naval officer Nicholas Monsarrat, though the screenplay by Eric Ambler omits some of the novel's grimmest moments. The film stars Jack Hawkins, Donald Sinden, Denholm Elliott, Stanley Baker, Liam Redmond, Virginia McKenna and Moira Lister.
