An instrument deployed off the coast of Lanai, Hawaii in Feb. 1994 to measure visible and near-infrared radiation entering and emanating from the ocean. The variations of the visible reflected radiation are referred to as the ocean color, a property from which other quantities such as the abundance of phytoplankton can be derived. MOBY will thus provide a timeseries database for bio-optical algorithm development and the calibration of such satellite instruments as SeaWiFS, MODIS, and MERIS.