The Merchant Marine suffered more KIA, based on the ratio of service members to KIA, than any other US service. The Merchant Marine had a KIA rate of 3.9% vs the USMC at 3.7%. This is not well known, and their service of getting supplies to not only feed civilians in the UK during the war, but supply the military was critical. Without the beans and bullets, the guy with the rifle ain't real useful for very long.
When fact checking my memory, I came across this page, American Merchant Marine in World War 2 which was interesting. Some of the stories on the link I have read before but then there was this one:
People went off to war at a very early age. The power monkeys in the Royal Navy during the age of Iron Men and Wooden Ships were children. Officers could be young teenagers or even children. Hard to believe a boy would be put in charge of men but it is what happened. Admiral Nelson was the Captain of a ship at the age of 20. I think he may have been the acting Captain for long periods of time on previous ships when he was the XO and his CO was sent home or sick. People back then did some things that were remarkable.
Later,
Dan
Yup, Dad was 100lbs soaking wet, and he almost drowned during training when they put a 50lb pack on his back and had him go hand over hand from dock to ship on a rope. Fell between the two and sank like a rock.