System for generating pressure waves for deep seismic surveys operating in an underwater environment below the surface, suitable for investigating subcrustal objectives for prospecting purposes in the search for hydrocarbons and/or minerals. The system comprises one or more autonomous underwater vehicles organized in swarms, independent and coordinated, each housing one or more autonomous acoustic sea sources with self- propelled striker pistons. This system is served by a system of supporting surface stations, for reprovisioning, recovery actions, checking the well- being of the single vehicles and swarms and maintenance. The system is capable of using both conventional and non- conventional self-charged acoustic sea seismic sources. The system is capable of replicating the effect of a conventional source operated from the surface. The seismic sea source of the non- conventional acoustic type, proposed herein, can release a high- intensity pressure wave produced by a system of two striker pistons, which does not consume air when operating as it does not disperse air or another gas in water and does not produce mass variations of the device during its functioning and allows the amplitude and duration of the sound wave emitted and characteristics of the emission spectrum, to be regulated.