The Coastguard was alerted and set about finding a vessel to assist Gareth Pearson, 38, and Duncan Pearson, 42.

The pair, who were taking part in the Atlantic Rowing Race, were picked up around eight hours later by a ship heading for Trinidad and Tobago.

Coastguards in the UK acted after they picked up the SOS signal.

The alarm set off by the men is known as an EPIRB - an Emergency Position Indicating Radio Beacon.

It can only send a distress signal which is then bounced off a satellite and on to one of a several rescue coordination centres.

Falmouth, being the UK's centre for international maritime rescue co-ordination, checked the signal and who the vessel was registered to.

The Falmouth Coastguard then liaised with the nearest rescue centre to where the signal came from which in this case was Fort de France, Martinique.

Requests were made for assistance and the call came around midnight Tuesday 24 January that the rowers had been picked up.

"Our colleagues at Fort de France, Martinique have worked closely with us, informing us of progress at every stage of this recovery," said Falmouth Coastguard Deputy Watch Manager Peter Ritchie.

"Falmouth Coastguard frequently works with other administrations during international search and rescue incidents," he said.