Another book I read as a child that I'd like to find was set in WWII around the evacuation of Dunkirk.
I think it was more a novella than a novel.
There was a man who couldn't fight in the war, due to disfigurement/disability possibly. He might have spent his days rowing on the marshes. He helped at the evacuation at Dunkirk by rowing across from England and died rescuing the soldiers trapped on the beach. I think he was probably jeered by the townspeople prior to his death and loved a girl who didn't love him back.
I read it 30 years ago.
I feel like Ernest Hemingway or some one similar wrote it, it seemed to me more like "high literature" rather than an easy read.