This article discusses a case study made on research carried out on a currently decaying inner harbor in a Cantabrian estuary (ría) (northern Spain), of which natural shelter conditions had led to the development of an old fishing vessel refuge against extraordinary winds and storms and the subsequent construction of a port. Previous research work has been on-going since 1978, seeking shore protection through simple beach restoration based solely on field observations with purely morphodynamic comprehension aims. The object of this investigation work is to now analyze possible definitive solutions for stabilizing the port's entry channel and maintaining its depth by using not only accumulated field experience but new measurements and numerical models.