CARPI formed an alliance with OCEANEERING, one of the largest underwater services companies in the world, and with Vriens Diving, one of the most experienced diving companies in Europe. As a result, almost all of CARPI's geomembrane installations can be performed underwater.

The geomembrane installed underwater provides the following benefits:

- offers the same benefits as the systems installed in the dry

- allows the facility to continue operations while installation takes place

- no significant quantity of water is lost and there is no need to refill the reservoir

- reduces environmental impact on fish life

- does not impact on downstream conditions (communities, fish hatcheries)

- does not affect recreational areas on the reservoir

- avoids potential problems caused by unloading and loading of the structure.

CARPI and OCEANEERING have jointly completed a project for the United States Army Engineer Waterways Experiment Station, Vicksburg, for the underwater installation of a CARPI geomembrane system on concrete hydraulic structures.

Underwater repair of dams has already been accomplished by installation of large geomembrane panels for leakage control, and of a full PVC geocomposite liner to restore impermeability at the upstream face.

In 1997, installation of the full system has been executed underwater, on Lost Creek dam in Northern California, USA. The Lost Creek project has been the first underwater installation of a waterproofing membrane system in the world.