Abstract: This device comprises a portable reservoir (2) suspended form a helicopter and provided with at least one lower hatch (21) for discharging the extinguishing liquid or water transported. The device comprises a vacuum pump (4) to create a vacuum inside said reservoir (2), a vacuum sensor (75) to regulate the vacuum created inside the reservoir (2) depending on the quantity of water to be loaded, several means to cause the opening of a lower hatch (21) of the reservoir (2) and the loading of water into the reservoir (2) as a result of the suction effect caused by the vacuum, several means for detecting when the reservoir (2) is full and several means for automatically closing the lower hatch (21) when the water load has reached a preset level.