A submarine power cable is a transmission cable for carrying electric power below the surface of the water.[
These are called “submarine” because they usually carry electric power beneath salt water (arms of the ocean, seas, straits, etc.) but it is also possible to use submarine power cables beneath fresh water (large lakes and rivers).
The purpose of submarine power cables is the transport of electric current at high voltage.
The electric core is a concentric assembly of inner conductor, electric insulation and protective layers (resembling the design of a coaxial cable).
Modern three-core cables (e.g. for the connection of offshore wind turbines) often carry optical fibers for data transmission or temperature measurement, in addition to the electrical conductors.
