It seems to me that two things are getting confused: the time when the shantyman is singing, and the time that the shantyman is singing about. If Liverpool Judies would have been used as a shanty for rowing the longboat, then "row" makes sense, whether or not rowing has anything to do with anything else in the song.

Can anybody say what kind of shanty this is, and what it would have been used for? Barry?

As for the meaning of Judies - lots of sea songs seem to assume that the only women the sailors will meet will be prostitutes, so trying to figure out whether "Judies" meant women or prostitutes is probably a moot point.

Jacob