On September 3, 1939, Barbara Rodman was lying in her berth on the SS Athenia in the grip of a second day of seasickness, trying unsuccessfully to persuade a stewardess who was insisting she should eat some food in the dining room to go away.

A short while later, as the 23-year-old American picked over her chicken, a torpedo fired by a German U-boat struck the liner – blowing a hole where her berth had been – in the first hostile act of the Second World War between Britain and Germany.

Miss Rodman had narrowly avoided becoming one of the first casualties of the war, but she was still in a sinking liner in the North Atlantic Ocean, hundreds of miles from safety.

What followed was "just as macabre an experience as anyone could possibly have," says the now 93-year-old widow, Barbara Wilson, from her home in Garden City, New York State...