Bert's whaling ship, 'Southern Empress', actually sailed out of Bromborough on Merseyside, and you can find an image or two online. Certainly not a ship requiring the services of a shantyman. In his notes for 'Leviathan', Bert claims that various crew members 'knew' some of the songs he presented on the LP, but I am pretty sceptical of whether he heard those songs on the whaler in the form he recorded them. He also claimed to have got songs - notably 'South Australia' and 'Off to Sea Once More' - from a singing group of old sailors from Barry - the Barry Riggers - who he met during the filming of 'Moby Dick'. I'm as certain as I can be that he made up the tune for 'Off to Sea'.