The British Seafarers' Union was formed at Southampton in 1911 by a group of members who seceded from the National Sailors and Firemen's Union. On the 1st January 1922 it merged with the National Union of Ships' Stewards, Cooks, Butchers and Bakers to form the Amalgamated Marine Workers' Union. Reference: Arthur Marsh and Victoria Ryan, 'The seamen. A history of the National Union of Seamen, 1887-1987'. Oxford, 1989.
Some editions of 'The British Seafarer' are included in the archive of the National Union of Seamen [MSS.175/5/2-5]. See also MSS.175/4/6 and MSS.175/7/ITF/7.