Well - no doubt I'm a significant presence in that group of "some people [who] don't", and you may rest assured that I feel duly chastened. However, in my very limited experience of this world, I've found that occasionally words and phrases have changes of meaning, and occasionally words and phrases have regional, dialect, jargon or vernacular usages that are not widely familiar outside a certain region or group of people. In this case, I question whether the phrase "reef the main boom" would not only have been composed and published by a Newfoundlander, but repeated by generations of singing Newfoundlanders, if it made no sense to them. These are, after all, people who tend to have some familiarity with things nautical. And while I have heard variations on other bits of the lyrics, I have never, until now, heard any variation on "reef the main boom". So I trust you'll understand if I don't unquestioningly bend to your authority and will, and continue to sing the "wrong" word.

(I'm going to put a question about "reef the main boom" on the Newfoundland songs thread ... ).