The hypothesis of isopycnal mixing was used in order to calculate the percentages of South Atlantic Central Water (SACW) in proportion to North Atlantic Central Water (NACW) in the intermediate layer between the density surfaces of sigma sub(t) = 26.5 and sigma sub(t) = 27.2 along a zonal section at 20 degree 10'N. In this profile the SACW distribution was "conserved" within an offshore distance of about 370 km from the African coast during two observation periods with a time lag of ten months. The SACW distribution along the section follows from the zonal energy structure of the geostrophic meridional flow within this layer. It is concluded that the intermediate geostrophic meridional motions are adjusted to the local profile of the continental slope H(x).