The short answer that this folk song describes an actual event that took place on February 8 and 9, 1889. That being said, there’s an almost endless array of discussion/argument about its wording. To give you just a taste of this backing and forthing, there are whole threads on discussion forums talking about why the song says “from Yarmouth down to Scarborough” when Scarborough is clearly north of Yarmouth. (Don’t believe me? Here’s the link to Google maps.) Since I’m no sailor, I can’t pretend to understand the reasoning as to why this wording is perfectly accurate in nautical terms, but it has something to do with the direction of the winds and currents. I think. And that’s just one small point in the whole mix. If you’re of a mind to do some reading yourself, google “Grimsby Town fishing disaster” and you’ll have more than enough to keep you busy. (Don’t just google “Grimsby Town” on its own, as all you’ll get is stuff about their football club—soccer to us ignorant Americans. Very interesting in its way, of course, but not much to our point here.)