There is some allusion to their class differences but it is not much of a hindrance. Jerry s biggest ordeal comes when he guns down what appears to be a nazi submarine- only to learn that by all counts it had to have been British. His own guilt, and the trouble with the Navy soon cause him to transfer to a bombing unit. His career and relationship with Mona are in shambles. As Jerry s future as an officer looks its bleakest and every flight possibly his last Mona begins an adventure of her own.
Shute brings to life the simplest objects as well- a car, a ship model, a radio set.
There are times when the characters get ahead of the reader - and sometimes the story moves too slowly. I would not want to underrate or give away the simple and ingenious conclusion to the story.