The ocean color component of the Aerosol Robotic Network (AERONET-OC) was established to support satellite ocean color validation activities in coastal waters through standardized measurements of atmospheric and marine optical quantities. Specifically, AERONET-OC can provide in situ spectral values of the normalized water-leaving radiance, LWN, and aerosol optical thickness, τa, through autonomous radiometers operating on fixed platforms in coastal waters. This work presents the rationale for the network and an overview of the measurement sites and applications. Focus is brought to the assessment of accuracies of coastal LWN from current satellite ocean color sensors: the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) onboard the OrbView-2 satellite, the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua platforms, and the Medium Resolution Imaging Spectrometer (MERIS) onboard the Envisat platform.