We present a simple, robust inversion for airborne oceanographic lidar profiles. A linear regression to the logarithm of the return is followed by a perturbation to obtain a backscatter estimate. For typical thin plankton layer examples, errors are expected to be <10% over 90% of the ocean. The inversion was applied to lidar data off the coast of Florida, where the correlation between lidar backscatter at 5 m and surface chlorophyll concentration from satellite ocean color measurements was 0.92.