Living in the Upper Peninsula of Michigan, not far from Lake Superior and right on Lake Michigan, it was an extremely popular song when I was young. We'd always see the big iron ore ships docked in Escanaba in Little Bay De Noc. I had Uncles and cousins that worked on those ships, but not on the Edmund Fitzgerald.
Lake Superior is a deep and massive lake...... 400 meters (over 1,300 ft.) deep in some spots. Cold, cold water. In the middle of summer, that lake temperature is at 56 - 64 degrees, depending on the year. If you've never felt that, its @#$%ing cold. Your legs will go numb.