Emma Vickers in Burscough was the only boatie I ever heard of with a traditional canal song, and I think she knew just the one! As far as I know, everything else we have heard on the folk scene since the fifties connected with the cut was made up.
This does not of course mean the boaties didnt sing in the pubbs. But it does strongly suggest they didn't sing songs about "Going up the Audlem fifteen with a load of snuff my brave boys"