The Mediterranean ocean observing community is committed to making regular surveys of the changing Mediterranean circulation. In the past, the Mediterranean has been sampled sporadically in time and space, mostly by national expeditions in regional waters. An outcome of the 43rd CIESM Workshop in 2012 (http://www.ciesm.org/online/monographs/Supetar.html) was a recommendation for repeated oceanographic surveys of the Mediterranean in a programme called Med-SHIP (https://doi.org/10.5670/oceanog.2015.71) to observe the changing circulation in a manner similar to the international GO-SHIP programme
for the global ocean. Mediterranean marine scientists have designed a plan involving 5 hydrographic sections on which comprehensive physical and biogeochemical variables following the GO-SHIP guidelines should be measured to the highest international standards on a regular basis. The Med-SHIP program consists of 2 north-south sections in each of the eastern and western Mediterranean (the western lines are now in the process of being recognized by GO-SHIP as “associated lines”) and a zonal section from the Strait of Gibraltar to the easternmost Mediterranean (line MED01, which is now part of the global programme GO-SHIP).