Probably you're looking for the harmony arrangement recorded by Steeleye Span in the 1970s, which has inspired many imitators.

I doubt you'll find it in sheet music form.

Steeleye's tune and lyrics were adapted, I believe, from the version in Stan Hugill's "Shanties from the Seven Seas" (1961). A more complicated version is in Cecil Sharp's "English Folk Chanteys," collected from chanteyman John Short around 1910.

A. L. Lloyd included Short's tune in "Folk Song in England" (1967).