In a series of experiments using a 1.6-mm-thick freezing tank, thin sections of salt water ice were grown which exhibit the same drainage features as natural sea ice. The tank design permitted photographs to be taken, while thermocouples mounted in the tank walls recorded the temperature profiles within the ice. Convection was observed in both the skeletal layer and in the brine channels by the flow of dyed brine. Flow in the skeletal layer was cusplike in appearance, consisting of narrow downflow regions separated by broad upflow regions. Above the skeletal layer, several brine channels were also usually present in the ice, and convective overturning occurred in these channels. The convection caused temperature fluctuations of 0.05¿C, which calculations show increase the vertical heat flux by 1%. The brine drainage channels, which were usually sloped 30¿ to 60≡ to the horizontally and vertically through the ice by melting their lower walls and freezing on the upper walls. An analysis based on the heat flux due to brine channel convection shows that convection can drive these wall movements. Our observations suggest that most of the bring movement in the channels is caused by recirculation of water from below the ice. On a small scale we also observed the formation of brine pockets from brine tubes.