Hi ... some days later ... sorry - I haven't had a moment at the guitar. But basically you could play the entire song in Eminor and D with the occasional B7 and one or two C chords. Start with Eminor and then change to D on "bed" in the first verse. Back to Eminor on "there stood a bold sea captain" and D on "my" and back to Eminor on "head".

Let me know how you go.

Callie