PRIOR TO EACH FIELD CAMPAIGN ALL LIGHT SENSORS WILL BE CALIBRATED AT BSI USING AN FEL STANDARD OF SPECTRAL IRRADIANCE THAT IS TRACEABLE TO THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST). A COMPACT OPTICAL PROFILING SYSTEM (C-OPS), FITTED WITH A COMPACT PROPULSION OPTION FOR PROFILING SYSTEM (C-PROPS) WILL BE USED TO COLLECT VERTICAL PROFILES OF DOWNWARD IRRADIANCE, UPWELLING RADIANCE, AND GLOBAL SOLAR IRRADIANCE AT 19 WAVELENGTHS SPANNING THE UV-NIR (320 865 NM) WITH 10 NM FWHM BANDWIDTHS. WATER TEMPERATURE IS ALSO MEASURED. A B I O SHA DE ACCESSORY ADDS SHADOWBAND OPERATION TO COMPUTE THE DIFFUSE-TO-DIRECT COMPONENT OF THE SOLAR IRRADIANCE. A BIOGPS ADDS TIME AND POSITION ALONG THE CRUISE TRACK AND AT ALL STATIONS. REAL-TIME DATA IS DISPLAYED TO FACILITATE THE SELECTION OF SEAWATER SAMPLING DEPTHS (E.G., THE DEPTH OF THE 10% AND 1% LIGHT LEVELS).