||A three-optical-sensor, user-defined instrument that may carry any combination of single-wavelength fluorometers or scattering meters. They are deployed on a CTD/IOP system or moored as fully autonomous sensors. The fluorometers can be configured (with typical sensitivities) for chlorophyll (470/695 nm, sensitivity 0.015-0.025 ug/l), FDOM (370/460 nm, sensitivity 0.184 ppb), phycocyanin (630/680 nm, 0.086 ppb), phycoerythrin (520/595 nm, sensitivity 0.086 ppb), uranine (470/530 nm, sensitivity 0.073 ppb) or rhodamine (520/595 nm, 0.086 ppb). The scattering meter can typically measure optical scattering at blue, green or red wavelengths (412, 470, 532, 650, 700 and 880 nm, sensitivity 0.002-0.003 m-1). The overall sensor can have a depth rating up to 6000 m depending on configuration.