Deep ocean water has a very uniform temperature, around 0–3 °C (32–37 °F), and a salinity of about 3.5% or, as oceanographers state, 35‰ (parts per thousand).
[3] In specialized locations, such as the Natural Energy Laboratory of Hawaii, ocean water is pumped to the surface from approximately 900 m (3,000 ft) deep for applications in research, commercial and pre-commercial activities.
When cold water passes through a pipe surrounded by humid air, condensation results.
The condensate is pure water, suitable for humans to drink or for crop irrigation.
Via a technology called ocean thermal energy conversion, the temperature difference can be used to run a heat engine to generate electricity.