Coastal and littoral ocean circulation simulation can make use of many modeling systems competing or complementary, which differ in the geometry represented (discretization grid, 2D / 3D), the equation systems used, the spatial scales / temporal simulations, and / or the numerical methods used to solve them. It is difficult to establish an orderly relationship between these different tools, each having its own merits on different aspects, such as the numerical cost, the accuracy of the schemes used, the completeness of the processes represented, etc. In the best of cases, these models are coupled together, each remaining used in its geographic area of predilection or supposed to be such. This IPL proposes to go beyond this approach by relying on the combined expertise of the Inria teams involved and to offer a more integrated approach, mutually enriching the different models and in particular by proposing a quantification and representation of the uncertainty associated with the different choices and approximations made. These questions relating to oceanography, ecology and geophysics raise major scientific obstacles with a strong socio-economic impact.