The seemingly unique broadside in the Bodl has no imprint and no distinguishing features such as woodcuts that wood help to date it. I am presuming the Kidson Collection broadside Roy Palmer mentions in The Oxford Book of Sea Songs is another copy of the same, but I will see Roy on 10th Oct at the VWML and ask him. the other song in the second column on the broadside is 'The Landlord's Song' and again I have not seen other copies of this. Other broadsides close to this one in the Bodl are printed by Such who was printing for just about all of the second half of the 19thc. By the type on the broadside I would guess at about 1880 but I could be 30 years out in either direction. Some of the words, especially in the chorus, hark back to other songs of which DB is partially a remake. When I last did research on the whole family I think the earliest prototype was the New York popular song 'The Knickerbocker Line' of about the 1870s which soon spread among the Great Lakes sailors and bargemen and was adapted to make such songs as 'The Cruise of the Bigler'. It's amazing how fast and far these songs can spread in such a short space of time, especially with the vastly improved communications of the late 19thc.