Less than half the competitors in last year's rally completed the event
A total of 50 teams have set off from Surrey to Cameroon to take part in a trans-continental car rally to raise £50,000 for charity.
The drivers, in vehicles with 1-litre engines, started the Adventurists' 2009 Africa Rally at Dunsfold Park race track on Sunday.
The teams have each chosen their own route from the UK and are expected to arrive in Limbe, Cameroon, in January.
Tom Morgan, founder of Africa Rally, said it would be a "proper adventure".
He added: "After starting the Africa Rally last year we've now got 50 teams from 11 countries setting off for the Saharan sands.
"Last year's inaugural Rally raised £65,000 and we hope to exceed this amount this year. The idea is to have a proper adventure while making a massive positive impact at the same time."
The end of the rally will be celebrated on 16 January in Limbe, Cameroon, with a public festival of traditional music and dance, organised in association with the Cameroon Ministry of Culture.
Participants are raising money for The Rainforest Foundation and Send a Cow and Ape Action Africa charities.
Less than half the competitors in last year's rally completed the event.