The Seafarers International Union or SIU is an organization of 12 autonomous labor unions of mariners, fishermen and boatmen working aboard vessels flagged in the United States or Canada. Michael Sacco has been its president since 1988. The organization has an estimated 35,498 members and is the largest maritime labor organization in the United States. Organizers founded the union on October 14, 1938. The Seafarers International Union arose from a charter issued to the Sailors Union of the Pacific by the American Federation of Labor as a foil against loss of jobs to the Congress of Industrial Organizations (CIO) and its communist faction.
Today the SIU represents mariners and boatmen who sail aboard U.S.-flagged vessels in deep sea, the Great Lakes, and inland waterways. Membership includes workers in the deck, steward, and engine departments. SIU members are represented aboard a wide variety of vessels, including: military support, commercial trade, tugboats, passenger ships, barges, and gaming vessels. Military support vessels operated by the U.S. Department of Defense’s Military Sealift Command (MSC) provide a key source of jobs for seafarers. MSC operates some 110 noncombat ships that support U.S. forces around the world..
SIU membership includes eligibility for access to healthcare, retirement, and education benefits. Educational facilities include the union’s Paul Hall Center for Maritime Training and Education at Piney Point, Maryland.
Source: Wikipedia, http://en.wikipedia.org/wiki/Seafarers_International_Union_of_North_America