The main scientific objectives of the cruises are threefold:

• to asses the large scale circulation in the Western Basin, evaluating the water masses and the fluxes at different key point in the basin (The North Current, The East and West Corsica currents, the Balearic front, Algerian Basin). The final goal was numerical modelling assessment.
• to identify and follow peculiar mesoscale structures such as surface eddies, modal weddies, submesoscale coherent vortices (SCV) meanders or filaments and explore the signature on the sea surface height (altimetry) and the acoustic impact (sound propagation).
• to observe and interpret the submesoscale dynamics such ageostrophic stirring, symmetric instabilities, mixed layer instabilities, subduction and convection.

The Protevs2015_leg2 campaign ran from 21 March to 10 April 2015 aboard the BHO Beautemps-Beaupré in the north-western Mediterranean basin. It focuses on aspects of physical oceanography (hydrology and dynamics). The main one is the dynamics of the North Current from the Balearic Sea, downstream, up to its roots upstream in the Ligurian Sea. The measurements attempt to capture not only the structures and characteristics of the mesoscale of the northern current, but also the sub-mesoscale associated with or at least near the northern current.