Ocean colour analysis is a proven tool for determining the health of ocean using oceanic biological activity through optical means. Phytoplankton pigment, chlorophyll_a, are indicators of equilibrium of CO2 concentration between atmosphere and ocean. The oceanic colour change due to chlorophyll_a provides the level of primary productivity whereas the colour change due to CDOM can be attributed to the level of pollution and higher particulate matter. The ability of optical sensor to map the spatial and temporal patterns of ocean colour over regional and global scales has provided important insights into the fundamental bio-optical properties and bio-physical processes occurring in the aquatic media. Chlorophyll, SST and PAR can be operationally scaled up to estimate primary production and estimate the fish stocks. This training focus on basics of marine optics, ocean colour remote sensing, and its applications such as mapping primary productivity, phytoplankton classes and algal blooms.