Question to the Ministry of Defence:

To ask Her Majesty's Government what assessment they have made of the UK’s ability to communicate with deep sea (1) military, and (2) civilian, vessels in the event of a total satellite blackout.

For Defence related communications to Military deep-sea vessels the Ministry of Defence would revert to Line of Sight (where feasible) or atmospheric bounce Radio services of a specific wavelength and frequency.

These capabilities are tested at periodical intervals in line with the Defence Exercise Programme.

For communications with civilian vessels, the Global Maritime Distress and Safety System (GMDSS) provides an internationally operated maritime communications service. Regulated UK vessels have radio installations capable of GMDSS communications to shore for their areas of operation. In ocean regions they may choose to have either High Frequency (HF) radio or satellite communications, but in polar regions HF is mandatory.