The Golden Vanity is a tune that was taught to Jim by Wayne Maret (original founder of the Dublin Overs, now in Hawaii). It appears to be based on the seventeenth century ballad called "Sir Walter Raleigh Sailing in the Lowlands". This leads me to believe it refers to the famous battle between the British navy and the Spanish Armada in which the British won even though they were outnumbered and outgunned. According to Hugill in Shanties of the Seven Seas, although it's not always considered a sea shanty, Hugill cites it as a capstan (a type of shanty with a specific rythym). Hugill lists 5 additional verses, but the story is still the same -- just more detailed.
Jim learned it from a friend, banjo enthusiast and old band-mate, Christopher Wayne Maret.