The importance of the oceans and coastal waters to the planet's ecosystem and food resources will require increasing level of global and local monitoring and control of such resources (by governments and international agencies). The submersible instrumentation package proposed herein has applications in maritime operations, fisheries management, water quality monitoring, littoral and coastal zone management. With its ability to simultaneously measure the upwelling and downwelling spectral radiative fluxes, this sensor will avoid the inaccuracies with today's single point sensors. This ability addresses a major gap in today's sensors by providing the data required for improved algorithms to estimate in-water constituents/properties. Hence this instrument has a broad appeal to the science community as a whole, and to monitoring agencies. NASA has a major role in the study of global climate and its impact on natural environments including oceanic biogeochemical cycling, and health of various pelagic and benthic ecosystems. The world's oceans play a crucial role in maintaining the health of the planet's ecosystems and serve as a valuable current and future food source for humankind. The oceans provide the only means of subsistence for many communities around the world, particularly the expanding coastal populations. The instrumentation package will be marketed to investigators in the government, academia, and international agencies that are involved in the study of oceans, coastal regions, and littoral regions of the globe. The proposed technology supports present NASA systems such as MODIS, SeaWIFS, MERIS, LandSat7, and future GEO-CAPS, HyspIRI, also various NASA/NOAA programs. It also expands on capabilities that are provided by the Marine Optical Buoy (MOBY) ocean color vicarious calibration observatory via on-site and on-demand calibration.