Experiments have been performed in a large wave tank in order to study the morphodynamics of rip current systems. Both accretive and erosive shore normal wave conditions were applied, the beach evolving through all the states within the intermediate beach classication, under the so-called down-state (accretive) and up-state (erosive) morphological transitions. Results show that any prescribed change in the wave conditions drastically increases the rate at which the morphology changes. The surfzone morphology tends toward a steady state when running a given wave climate for a long duration. We quantitatively describe a full down-state sequence characterized by the progressive evolution of an alongshore-uniform bar successively into a crescentic planshape, a bar and rip channel morphology, and a terrace. From the analysis of a large dataset of dense Eulerian measurements and bathymetric surveys, we depict several feedback mechanisms associated with wave-driven rip current circulation, wave nonlinearities and the seabed evolution. At rst, a positive feedback mechanism drives a rapid increase in the rate of morphological change, beach three-dimensionality and rip intensity. By the time the sandbar evolves into a bar and rip morphology a negative feedback mechanism, characterized by a decaying beach change rate and an increasing beach alongshore uniformity, overwhelms the former mechanism. An erosive sequence characterized by both an overall ohore bar migration and an increase in beach three-dimensionality is also described.