A synthesis and review of the physical oceanography of the GIN Sea (Greenland, Iceland and Norwegian Seas) is presented. An accompanying bibliography is included from 1972 through 1985. Some 1986 works are also noted. Emphasis is placed on describing the GIN Sea as a major semi-enclosed basin that plays a role unique among the world's oceans: by providing a strong two-way advective exchange between the ice-covered Polar Sea and the North Atlantic Ocean and at the same time acting as the primary site for Northern Hemisphere bottom water formation. The water masses for the GIN Sea are defined, in a manner as consistent as possible with the literature. The large-scale oceanographic and meteorological factors influencing the water mass formation and circulation are described. A sample calculation of the various horizontal and vertical thermohaline-driven exchanges is given.