Briton Ben Southall said he will miss his mom's Sunday roast as he began what's been dubbed the "Best Job in the World" - a six-month contract to serve as caretaker of a tropical Australian island.

The 34-year-old former charity worker bested nearly 35,000 applicants from around the world for the dream assignment that started on Wednesday to swim, explore and relax on Hamilton Island in the Great Barrier Reef while writing a blog to promote the area.

He was selected for the USD 120,000 gig by officials from the tourism department of Queensland state in early May.

Southall said he hit the ground running on his first day on the job after returning to the island from England where he spent almost two months.

"Now that I've got back out here, all of a sudden it's really hit me again ... it's going to be very full on," he told Nine Network television.

Southall said his mother cooked "a good roast" for the family on Sundays. "That was just one of the things I said was going to obviously be missing out of my routine," Southall said.

"What I'll actually be doing is donning the apron, sticking the tongs in my hand and sticking the shrimp on the barbecue," he added. "So I can adapt particularly well - don't worry about that."