The hydrographic conditions of the Ibiza Channel were studied in successive surveys during November 1990, March 1991 and twice in July 1992. From a hydrographic viewpoint we must emphasize the importance of the intrusion of Modified Atlantic Water (MAW) with its associated front as a result of mesoscale processes, and the presence of the seasonal Winter Intermediate Water (WIW) which fills the entire width of the channel in the form of a layer between 300 or 400 m thick. This water mass affects the dynamics of the Ibiza Channel by a reduction in the exchange, hiding the seasonal characteristics of the Levantine Intermediate Water (LIW), which we consider to be one of the causes of the circulatory change in the channel. The combined action of the different water masses and their production cycles give rise to readjustments in density that could favour the presence of gradients on the continental slopes and Deep Water (DW) on the sill of the Channel. The geostrophic transports of the different water masses have been calculated.