In view of the need to solve problems related to the population's access to sufficient drinking water, the search for submarine discharge zones is currently the most important economic task. Infiltration waters generated within the land, being filtered through bottom sediments, are directed to the seas and oceans and are irretrievably lost for practical use. According to numerous data on the dynamics of underground water supply systems, the movement of underground flows in coastal areas under undisturbed conditions is always directed towards the sea, where discharge is carried out. Infiltration waters flowing from the land to the seabed are predominantly distributed in the shelf zone, but under favorable conditions (tectonic disturbances, paleo-river beds, etc.) their flows can reach the continental slope, so significant areas of the ocean shelf deserve to be explored for fresh and slightly salty, brackish water. In some countries, they are already used to provide water supply. The article assesses the feasibility of practical use of subaquatic waters using specific examples. It analyzes hydrogeological potential, economic factors, and presents technical concepts for water intake, transportation, and treatment. Based on these factors, we are analyzing the possibility of replacing the seawater desalination process with its extraction from submarine underground horizons on the shelf. The article provides a comparative assessment of energy consumption obtained from fossil fuels in the process of seawater desalination and its extraction from underwater horizons. The material presented in the article shows that there are no insurmountable obstacles to the use of submarine discharge waters as an additional source of drinking water.