They are four men, including a teenage boy, on a boat no bigger than a large room, for 24 hours a day for four months. And they have no spare underpants.

Pete Goss, the famous West sailor-adventurer, and his family are attempting to recreate the epic voyage of a tiny boat that sailed from Cornwall to Australia in 1854.

Back then, seven Cornishmen escaped poverty by building their own boat and sailing it to a new life Down Under, but even they had at least one change of pants.

The calamity occurred when the crew went to the launderette to pick up the last of their clean washing. Obviously, being men, the last load contained their entire stock of underwear. The launderette, sadly, had closed for the day, with their undercrackers behind its locked doors.

Again, being men, they thought they would rather not miss the fair wind on the evening of the launch, so they set sail rather than wait for the morning when they would be reunited with their clean pants.

After three days, however, the reality sank in and the crew requested an elaborate underwear rescue mission that involved dropping their spare pants from a light aircraft so they could collect them from the sea.

But again calamity struck. A storm blew in across the Bay of Biscay and the underpant-laden plane, piloted by mission control back-up man Stuart Elford, was grounded. By the time the skies cleared, the little 37ft long boat was out of range.

So now Pete Goss, 46, his son Eliot, 14, his brother Andy and brother-in-law Mark are continuing down the coast of West Africa with four pairs of pants between them. And they are .

The family crew is attempting to sail 12,000 miles to Australia, and reckon it could take them four months. They hand-built the boat, named The Spirit of Mystery after the original 1854 vessel, and have vowed to keep true to the original voyage. They are not allowed to make landfall before Cape Town, where the original crew of seven made their first stop.

Mr Elford said: "All we had to do was buy several packs of underwear, pack them in a floating waterproof bag and fly to their latest position.

"We could get there in less than two hours, make a drop beside the boat and return. But we were scuppered by the weather."

Although the tiny boat is a faithful recreation of the original Mystery and the crew are determined to navigate by the stars, it does have some 21st-century back-ups, including an engine for use in emergencies only, and a global positioning device.

"But I'm sure a lack of underwear will not be a major challenge compared to what else the team will face," added Mr Elsford. The crew of the original Mystery would not have had this sort of support, so perhaps it is fitting that we didn't make the air-drop."