The Danish Seamen's Union was a trade union representing sailors and other workers ships in the Danish merchant navy.
However, the union was generally more radical and left-wing than the LO, and so in 1912 it left the federation.
It joined the International Transport Workers' Federation in 1928, and rejoined LO in 1937.
[1][2] After World War II, the union's membership entered a long-term decline, with smaller crews and many ships using flags of convenience.
In 1975, the union again left the LO, following a dispute about quotas.