CoverFreak collected a series of modern covers of sailor songs. My ongoing favorite is this one, by Loudon Wainright. It was also featured in the traditional song companion album to "Pirates of the Caribbean". Just an excellently filthy song, and more in line with what was actually sung on ships, I’d bet. From http://coverfreak.com/2009/01/11/a-sailors-life-for-me/
"This song is from the massive Norwegian Prince tribute album Shockadelica that the Little Guy had pulled from the market. It’s a shame he did, because it’s full of wonderful covers like this one. It’s a very sad song. It sounds like the singer is resigned to the loss of his lover but he’s not quite over her yet." From http://coverfreak.com/2009/05/17/the-rainy-season/
Metafilter user cortex covers Laurie Anderson’s meisterwerk. I like it. A lot.
"Here’s an attempt to cover O Superman without copying it; no synths, no vocoders, no sampling or looping."