Roud 1671, where most examples listed are Scottish; there are also several from Canada and Northern Ireland, and only one from England.

The easiest way to link to results at the Traditional Ballad Index is to run a search there, rather than using a search-engine cache or linking to a whole section. Thus:

http://www.csufresno.edu/folklore/ballads/HHH739.html (The Sea Apprentice)

As the TBI notes, the DT file Prentice Boy, copied from Helen Creighton's Songs and Ballads from Nova Scotia, assigns a Laws number that belongs to a completely different song (and, sadly, fails to mention even the name of the singer from whom the song came. He was Ben Hennebury, of Devil's Island, Nova Scotia).