I saw this movie when I was in high school.
I think it was one of those movies which got me 'into' movies. I remember the tension in the story, because my parents grew up during the Blitz in London and England. My mother was younger, but she said that the story was true to what she heard from her father - Royal Marine AA gunner - and this is why it was memorable to her.
The acting is solid in this and the storyline - packed lifeboat at sea - is the prototype for other movies that followed it.
Good solid WWII movie which is not just WWII setting with modern equipment.