This study focuses on the dynamics and conflicts derived from the occupation of the coastal areas of the Province of Concepcion due to the growth of both artisanal and industrial fishing activities. The objective is to show the scope of the legal control of the coast by the State of Chile through the Navy and to illustrate and examine cases related to the development of mechanisms for the adaptation of artisanal fishermen to the progressive enclosure of coastal and marine spaces. It is argued that the fishermen subsisted under progressive precariousness and instability, due to an ambivalent state position that ended up decisively favoring the industrial sector at the middle of the twentieth century.