The Agulhas Current system is a complex interplay of currents and eddies with the bathymetry. Components such as the East Madagascar Retroflection and the Agulhas Return Current evolve significantly over a month, and they are thus not adequately resolved by infrequent research–ship cruises. This paper contrasts the abilities of three different spaceborne sensors for monitoring these complex regimes. A key parameter is sea–surface temperature, measured by both infrared and microwave radiometers. Ocean colour observations of chlorophyll can also be used to distinguish between water masses.