Conceived as a major new tool for climate studies, the Surface Water and Ocean Topography (SWOT) satellite mission will launch in late 2021 and will retrieve the dynamics of the oceans upper layer at an unprecedented resolution of a few kilometers. During the calibration and validation (CalVal) phase in 2022, the satellite will be in a 1- day-repeat fast sampling orbit with enhanced temporal resolution, sacrificing the spatial coverage. This is an ideal opportunity - unique for many years to come - to coordinate in situ experiments during the same period for a focused study of fine scale dynamics and their broader roles in the Earth system. Key questions to be addressed include the role of fine scales on the ocean energy budget, the connection between their surface and internal dynamics, their impact on plankton diversity, and their biophysical dynamics at the ice margin. AP acknowledges support from the Spanish Research Agency and the European Regional Development Fund (Award no. CTM2016-78607-P/PRE-SWOT). Part of the research for this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. JW and L. L. Fu acknowledge the support from SWOT mission. We thank the “Délégation Générale de l’Armement” which funded through the “Programme d’Etudes Amont Protevs II” the 2018 PROTEVSBIOSWOT campaign (PI Franck Dumas from the Service hydrographique et océanographique de la Marine) and makes a fruitful collaboration with the SWOT Science Team possible.