In September 1994 personnel from the Naval postgraduate School (NPS) and the Naval Oceanographic Office (NavO) conducted an experiment off the coast of Mississippi to determine the accuracy of infrared sea surface temperature (SST) measurements made from a small boat1 and the effect of these measurements on estimating the evaporation duct height (z). It was found that infrared SST measurements are highly accurate, agreeing closely with SST measurements made by other methods, and that a small relative error in the SST measurements can lead to large errors in z estimates. However, it is difficult to predict the effect a given error in SST will have on the resulting z estimate, due to the complex relationship between SST and z