International research has shown that large and ancient volumes of groundwater exist under the seabed offshore and underneath islands. Water qualities range from directly potable to lightly brackish, while associated volumes may surpass the size of onshore groundwater systems. Worldwide, numerous discoveries have been made in recent years. These volumes are related to the historic movement of coastlines worldwide, especially during the last ice age that ended some 12,000 years ago. Actually, many large onshore groundwater, such as for instance found on the Arabian Peninsula, were also formed in this period.
Innovative use of technology from the water and petroleum industries allows a sustainable development for extended periods at a cost considerably lower than through any means of seawater desalination. And at volumes which make it an interesting option for either small demands or large municipal and industrial demands. It can therefore be seen as an extensive and interesting addition to water sources for more water-starved areas.