Current ocean color sensors, for example SeaWiFS and MODIS, are well suited for sampling the open ocean. However, coastal environments are spatially and optically more complex and require more frequent sampling and higher spatial resolution sensors with additional spectral channels. We have conducted experiments with data from Hyperion and airborne hyperspectral imagers to evaluate these needs for a variety of coastal environments. Here we present results from an analysis of airborne hyperspectral data for a Harmful Algal Bloom in Monterey Bay. Based on these results and earlier studies we recommend increased frequency of sampling, increased spatial sampling and additional spectral channels for ocean color sensors for coastal environments.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.