"It seems a lifetime ago when I sat down in January to plan and film my 60 second video application. At times I still can't believe I was successful in being offered what has to be the most sought-after job in the world," Southall was quoted as saying by the BBC.
The 34-year-old British charity fundraiser beat more than 34,000 applicants to the position in a highly publicized contest that was part of an innovative marketing campaign by Tourism Queensland which attracted almost 35,000 video entries from some 200 countries.
He was named as the successful candidate in a reality TV-style ceremony by Tourism Queensland on 6 May.
Southall's duties include exploring the islands of the Great Barrier Reef and reporting back to Tourism Queensland and the world via blogs, a photo diary, video updates and interviews.
He, accompanied by his girlfriend, began his six-month job earlier by settling into his new home, a luxury ocean-front villa called Blue Pearl, the news channel said.
Southall said he was looking forward to living on a "nice piece of paradise," but added he would miss his mother's cooking.
