McGrath, I'm of a mind with you, I think - it's the "splendid battle" that gets me. There's nothing splendid, it's just what you do, bcos the next time someone's in trouble it could be you. It's certainly heroic, but quietly so in doing what you know you should, not in the sense of fighting "splendid battles". Re-reading it, the second verse is much better. Generally for something like this I prefer songs that let the story speak for itself - instead of just proclaiming how brave the guys were, tell the story straight and have the audience realise themselves how brave these guys were. I think that has a better impact, especially for something like this where the story's so strong. (BTW, I don't like the word "story" for this since it seems to imply fictionalising it, but English doesn't have a better word for it - the French "histoire" conveys it better, but "history" isn't really a synonym for "story" in English.)
Nutty, that's a great resource! For the benefit of others, here's a link: Bodleian Library Broadside Ballads
Jon, I'd be interested to see anything you come up with on lifeboat songs from other regions.
As far as working out a song goes, I need to do more research. The site McGrath linked to has a transcript of the Southport logs which is incredibly useful, but I'll need to find out more about the Lytham and St. Annes crews' stories. Lytham lifeboat house has a display about this, so I'll see what I can dig up next time I'm home.