Abstract
Data specifically selected from the total available data set have been used for an isentropic analysis of the southwest Indian Ocean. Components of geostrophic velocity at the depths of the various isentropic surfaces have been calculated to aid in the interpretation. It is found that during the northeast monsoon season the Agulhas Current derives its supply of water from different sources at different depths and that at depth a large measure of recirculation of Agulhas Current water takes place. The concept of a southwest Indian Ocean gyre, postulated before, is confirmed.