Q above listed various sources for Capt. W. B. Whall's book "Sea Songs and Shanties". It's still available (£9.95 + p&p) direct from the original publishers, and as far as I can see has never been out of print:-

Sea Songs and Shanties at Brown, Son & Ferguson

For anybody interested in ships and shipping, from the days of sail right up to modern times, their catalogue is a treasurehouse:-

Brown, Son & Ferguson Catalogue

Happy browsing!