The past three decades have witnessed development of a multitude of sensors and a plethora of analytical (processing) methodologies. The main sensors pertinent to reef assessment are listed in Table 1. This list is not exhaustive, since it ignores recent instruments which have not been widely reported in the literature [e.g. LISS (linear imaging self-scanning) sensors on the Indian Remote Sensing satellite). The most widely used satel- lites are Landsat MSS, Landsat TM, SPOT XS and SPOT Pan (see Table 1 for explanation of abbrevia- tions). The literature concerning their relative capabili- ties for habitat mapping is disparate, and very few comparative assessments have been undertaken.