This Volume collects a series of key-note lectures delivered at the fourth "Oceans from Space" Symposium, held in Venice, Italy, in 2010. The revisited postscript in the title identifies it as the ideal follow-up of the legendary Oceanography from Space, edited by J.F.R. Gower and published in 1980, following the very first edition of "Oceans from Space". This series of conferences, which are held every 10 years only, is designed as a periodical state-of-the-art review of satellite oceanography, providing both an outline of current research, as well as a forum to debate topical issues. The "Oceans from Space" Venice 2010 lectures, authored by a unique group of prominent scientists, address virtually every facet of oceanographic remote sensing. All salient marine applications of passive and active techniques are covered in the present collection. The main results already achieved, or soon to come, demonstrate the potential of Earth Observations to help explore the dynamical and bio-geo-chemical features of the World's Oceans.