Three men are giving up Christmas to drive an ambulance 3,500 miles (5,632km) from Anglesey to Gambia.
The trio are looking for sponsors and spare parts for the Land Rover
Their 1969 ex-military Land Rover ambulance will then be donated to a health clinic in Africa.
One of the drivers, Guto Roberts, said it was going to be "one heck of an adventure".
They will set off on 19 December with a convoy of about 20 vehicles taking part in the Plymouth Banjul Rally to raise money for health care in Gambia.
Mr Roberts, Huw Owen and David Griffiths, who are all 27 and from Anglesey, will sleep in the back of the ambulance en-route and hope to arrive in Gambia after three weeks on the road.
Mr Roberts described the vehicle as "very sturdy, very slow and very thirsty".
The men are working with Cyfeillion Sankwia Friends, a charity based in Amlwch which supports education and health initiatives in Gambia.
They will also be raising money for Tyddyn Mon - a farm on Anglesey which employs people with disabilities - and Ysgol y Bont special school at Llangefni.
"In the back of the vehicle, which has a long wheel base, there are four stretchers which will be ideal for the clinic in Sankwia," said Mr Roberts .
"We'll sleep in the back on the way because it makes things easier and means we have to pack less stuff, and on rest days we can just nip in the back for a nap before getting back to driving."
The journey will take them through Europe to Morocco, Mauretania, Senegal and then Gambia, crossing the Sahara desert.
"We'll spend Christmas in Marrakesh in Morocco, then the new year in the middle of the Sahara somewhere."
None of them has taken part in such a challenge before although Mr Griffith's day job as a tractor mechanic might come in useful.
They are hoping that by joining up with the Plymouth Banjul Rally they will get support and be able to employ guides to take them across the desert.
"We've been warned that we need guides if we are to avoid mine fields in the Sahara," Mr Roberts added.