The Tara Oceans voyage took place on the schooner “Tara” from 2009 to 2013 and visited all oceans to collect samples and data in order to study the relationships between ecosystem biodiversity and function and the physical-chemical oceanographic environment (water mass, transport). The ship was adapted for modern oceanography. Scientifi c instruments were mounted on a dedicated CTD frame and installed on an underway fl ow-through system. Data were sent daily to Coriolis and and those daily data sent accounted for about half of the oceanographic data sent over the period. Post cruise calibrations were performed leading to a high quality dataset comprising both surface data over a distance of about 60000 nautical miles on all oceans and depth profi les from 700 CTD casts.