The general objective of the BELCOLOUR-2 project is to improve the quality of existing optical remote sensing products for marine and inland waters based on new knowledge and to develop new products (including primary production and partial pressure of CO2) for key applications such as aquaculture support and air-sea CO2 flux estimation. BELCOLOUR-2 will build on the experience built up in the BELCOLOUR-1 project whose results can be found at http://www.mumm.ac.be/BELCOLOUR. Key issues to be dealt with in BELCOLOUR-2 include automated data quality control, validation, phytoplankton optical properties and taxonomic groups, atmospheric correction, primary production, air-sea CO2 flux estimation and the preparation of new technologies including future satellite-based hyperspectral sensors, geostationary sensors and unmanned airborne vehicules.