A British charity fundraiser is one of 16 finalists for what has been advertised as the best job in the world: a £70,000 salary to be "caretaker" of palm-fringed Hamilton island on the Great Barrier Reef.

Ben Southall, 34, of Petersfield, Hampshire, beat 34,000 applicants from around the world to become the only Briton on the shortlist for the job, which is proving to be a public relations masterstroke by tourism chiefs in the state of Queensland, Australia.

Southall, who describes himself as "the adventurous, crazy, energetic one", has never been to Australia but last year visited more than 30 countries in Africa funded from his own pocket and, along the way, inspired people to donate £20,000 to charity.

Today he said: "I had a phone call last night from the big chief boss out there in Queensland to say: 'Well, done mate...'. And he called me 'mate' about four times so I knew it was the real deal."

Southall will now travel to Hamilton Island for a reality TV-style face-off with the other finalists which, over five days starting 2 May, will involve snorkelling, sailing and gorging on resort food with each day ending with a media interview.

"There's going to be a lot of experience of what the island has got to offer, but there are aptitude tests, there are fitness tests," Southall said. "I don't expect to fail in any department. I expect to have high average and that's how I think I'm going to get through."

The winner, who will start a six-month contract in July, will be required to work 12 hours a month and will enjoy free accommodation in a three-bedroom villa on the island, described as the "jewel in the crown" of the Whitsunday islands by the Queensland Tourist Board.

The only other requirements are that the winner travel around the surrounding waters and some of the hundreds of other islands that dot the reef and blog about their experiences in English. Southall, who as well as driving across Africa, has ridden an ostrich and lists his interests as scuba diving, bungee jumping and mountain biking, says his best chance of winning is being himself. "People who do the best on reality TV shows come through as honest and decent. I'm really an outdoors person, I really like exploring."

May has been chosen for the finals because it is when the wet season has receded, humidity has dropped, cyclones are less likely, and the deadly box jelly fish are nowhere to be seen.

If he wins, Southall plans to ship his Land Rover to Australia and travel around the outback. He said he has been inundated with good luck messages. "Everyone has been emailing me. The first ones to come in were from the other UK entrants. They were obviously sitting there waiting and watching and in a very British stiff upper lip way said, well done, off you go and represent the Brits."

After news of the job emerged in January, the story was picked up around the world and the islandreefjob.com website inundated with applications. Queensland's tourism minister, Peter Lawlor, said the idea had generated publicity worth millions of pounds.