In 99% of cases sea shanties no longer function as work songs. They are entertainment/pleasure. There is absolutely no reason why ANYONE should not add any accompaniment they want to. Most of the wankers who say shanties have to be unaccompanied have never been to sea anyway. As it happens I simply prefer to sing most of my shanties unaccompanied but I'm certainly not averse to being joined by a fiddler on any of them and squeeze boxes are no more traditional for sea songs than any other instrument.

As a squeezebox player who contemplated playing on the Brid pleasure boats, I was put off by the previous player complaining his reeds were rusting. Jim Eldon and his fiddle have been playing all summer through on the Brid pleasure boats for at least 20 years.