Abstract: Disclosed is a device for the automatic sinking of containers and hulls, including: valves, installed in a first closed configuration and having an airtight seal, susceptible of assuming a second configuration that is irreversibly opened when the external pressure exceeds a predetermined tolerance threshold, the second open configuration being adapted to make air exit from the internal space and make water enter from the outside, the at least two valves being positioned in proximity to two edges, opposite each other, belonging to two lateral surfaces of a container; support which surrounds each valve and adheres to the lateral surface of the container, by way of a coupling system that is adapted to ensure impermeability; protection grids, one placed on the outer side and one on the inner side of each valve, adapted to protect from impact and from extraneous objects which could compromise the functioning thereof.