This sector involves the transfer of telecommunications (telecom) and power between the UK and other countries and among the islands of the UK through subsea cables.

There are some 18 000 km of telecommunication cable and 2368 km of power cable on the UKCS. The overwhelming majority of international communication transmissions are through fibre optic submarine cables with the highest proportion (43%) passing through Region 4 (Western Channel and Celtic Sea). The only international power cable link is currently with France. Remaining cables provide links among the islands of the UK, for example, mainland UK with the Isle of Man and the Scottish Isles.

An indicative GVA of £2.7 billion was estimated for telecom cables based on the number of international phone calls. However, this figure does not include the value of internet and data capacity which are now the primary commodity and which are increasing. The true value of telecommunication cables should incorporate both the value of the traffic which is carried and the significance held by the UK as a key strategic location for international systems looking to reach markets in America, Europe, Africa and Asia. These are difficult to capture in market value terms but are significant. The capacity from the main interconnecting power cables, which is currently 2540 MW from 212 km of cable, may be used as an indicator of the scale of the activity.

Impacts from cable installation on the seabed are short term and spatially minor. Although there is potential for the electromagnetic fields associated with high voltage power cables to impact on animals that are sensitive to such fields, considerable research suggests that the spatial extent is small and, if the cables are buried to more than 1 m, the impact will not be significant.

The deployment of power cables has been steadily increasing due to increasing demand within the UK and demand for improved security and stability in electricity supply. Deployment of power cables is likely to increase as we develop more offshore renewable energy installations.

The UK telecommunications sector went through a period of correction from 2002 to 2006 following the growth and downturn associated with the Dotcom bubble, but major domestic and international systems are now being installed. Future developments in this sector are focused on extending the global reach of the sub-marine networks, investing in higher capacity circuits and increasing resilience by operating networks over a number of different cables.