The aim is to raise awareness about a global lack of clean drinking water and funds for the charity WaterAid which works with some of the world’s poorest communities to improve access to safe water, sanitation and hygiene.

Before setting sail, the crew of four and their captain, former BBC TV ‘Tomorrow’s World’ presenter, 86-year-old Anthony Smith, filled five of the raft’s 18 ft cross-pipes with fresh water for drinking, cooking and washing. They plan to catch fish and net plankton to supplement their onboard diet. "Plankton is good enough for the blue whale, the biggest creature on earth, to eat, so it's good enough for the An-Tiki crew!" Anthony said.

They will sail to Eleuthera in the Bahamas where in 1940, a small lifeboat, the ‘Jolly Boat’ finally landed after 70 days sailing across the Atlantic. It was launched from a British merchant ship, the SS Anglo Saxon, which had been torpedoed and sunk by a German vessel. Only two of the seven survivors were still alive when they landed after drifting for 2,300 miles. Very thin and dehydrated, they had existed on occasional rainfall after supplies had run out.

In the late 1990s, Anthony helped to get the Jolly Boat for the Imperial War Museum in London and wrote a book about the survivors.

To learn more about the voyage and see updates on its progress visit www.an-tiki.com