drilling hdd of one or more boreholes from the land in a zone close to the coastline and directed towards the sea passing through zones expected to provide sufficient permeability both because of porosity and because of fracturing to ensure at all times the replenishing of the marine aquifer to be exploited and until reaching the seabed in a final slightly upward section the hdd system allows the drill head to be guided to drill very long holes more than 600 m within the strata of the productive aquifer this technology allows holes to be drilled from the land which come out in the sea without affecting the intermediate section for the localization of the drill head magnetic navigation systems are used with a localization precision of the order of centimeters allowing the guiding of the borehole to achieve optimum objectives this part of the process is known as pilot drilling after pilot drilling the hole is widened by pushing withdrawing the detritus by means of mud fluid injection and then introducing a tubular drain in the gallery to take up the water through the productive strata the openings of the drains whether they are drills or holes are arranged only where the productive zones are expected before placing the drain where the ground permeability is most favorable and in order to avoid collection from undesired zones the end of the drain can be accessed from the seabed in which case it is equipped with a cap that can be opened for maintenance or it is buried slightly such that the tube remains underground and inaccessible from the seabed or sea bottom in the case of multiple installations the drains would preferably be placed.