My father, as a 15 year old in 1940, endured the Blitz as a rooftop fire spotter. After that, he came to the conclusion that being on the Atlantic convoys was somehow safer, or at least one ate better. He was a British Merchant Navy A.B. and then officer from 1941-52, and did the Murmansk run, the Atlantic run, and went all the way to Australia during the war, and then went whaling in Antarctica afterwards, when that still seemed like a good idea. To the end of his life, he sported a forearm tattoo with the Rose of England over an anchor, a funny thing for a Welshman with an Irish last name to sport, but it may have been merely to celebrate a Lisbon whorehouse deflowering when he was 17. Ah, good ol' Dad.
He was reportedly born with a caul, alleged to save one from a death from drowning, and while I can't speak to that, I do know that both times that he "jumped ship" during the war (jumping ship meant declining to sign back on to another voyage in hopes of finding a better berth in another ship), both ships in question went down with all hands. I also know that he never attended a MN reunion, because almost all his wartime friends were dead.
But he did wear a blazer with the Merchant Navy crest, and as he died in '06, I have it and the very few mementos of his service that survived from then until now.
The startling thing to note is that he had four years of wartime service, and yet was barely 20 in 1945. It is a different world today.