Breaking waves wet the alarm, triggering the Mayday beacon

Heavy seas set off the Emergency Position Indicating Beacon while the Pink Lady was at anchor.

The crew - from Dorset, London, Surrey and Wales - have already faced a 45ft freak wave and are less than 600 miles from ending their voyage from Canada.

They contacted Falmouth Coastguard to explain, after they saw the alert.

Storms and icebergs

Breaking waves made the emergency alarm wet and triggered the beacon, which is designed to go off manually or when submerged at depth.

Firefighter Mark Stubbs, 40, from Poole; ex-SAS diver Peter Bray, 48, from Bridgend; journalist Jonathan Gornall, 48, from London; and digital mapping specialist John Wills, 33, from Farnham, are battling to cross the "Lizard Meridian".

The line stretches from Lizard Point, Cornwall, to Cape Finisterre, Brittany - the most westerly point of France.

They are then due to head up the Channel towards Falmouth to land at the town's National Maritime Museum.

On Friday, they were hit by a 45ft freak wave although no-one was hurt - two weeks ago the crew were forced to row 45 miles out of their way to avoid heavy storms.

Days after setting off on 30 June they faced storms and four times the usual number of icebergs off Canada.

They are hoping to raise �50,000 for the British Heart Foundation.