Results of a detailed expendable bathythermograph survey in the northern Tasman Sea are presented. The Tasman Front, with its origin in the edge of an East Australian Current eddy, extended throughout the survey region. The front marked a coherent, meandering, zonal jet which crosses the Tasman Sea and hence links at least part of the East Australian Current to the other western boundary currents in the subtropical gyre. The frontal meandering derives from both the variability of the East Australian Current system and the topographic effects of the major ridge systems in the north Tasman Sea. The front is less distinct over the crests of these ridges. The flow field in the survey area contained a number of anticyclonic eddies, and current records show that the oceanic eddies are long-lived features similar to the eddies in the East Australian Current.

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Hydrographic observations over the west coast shelf during the Tasman Boundary Experiment (TASBEX) in 1986/87 are presented. Temperature dianges over the shelf were related to mixed-layer development, shelf waves, and seasonal changes, with wind-driven upwelling being important close to the coast. During upwelling, a surface coastal current was observed and at times a weak undercurrent or countercurrent developed. Changes in freshwater inflow resulted in changes in the depth of the lowsalinity surface layer. In the north, flows were generally weaker than in the south, where the shelf is narrow and the Southland Current dominates. Changes in the position and strength of the Southland Current were observed and on one occasion the response to a wind change event was a relaxation of the flow to a coastal Southland Current regime.

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