ONE of aviation's great mysteries appears to have been solved and is likely to be attracting the interests of divers off the Andaman coast soon.

About 20 metres down on the seabed off Burma, according to an Australian filmmaker, lies the plane in which aviation pioneer Charles Kingsford Smith and copilot Tommy Pethybridge disappeared while attempting to break the flight record between England and Australia.

The mystery of their fate rivals that of American aviatrix Amelia Earhart, who went missing in 1937, two years after Kingsford Smith's 'Lady Southern Cross' vanished.

Filmmaker Damien Lay said in Sydney today that he is 100 per cent certain he has found the final resting place of the early flying ace.

He and his and his search team locating the wreckage of the 'Lady Southern Cross' off the Burmese coast on February 24.

During the five day search, which involved 63 dives and sonar tracking, Mr Lay said he found the wreckage under 20 metres of water and mud in a bay of remote Aye Island.

The deeds of Kingsford Smith and solo pilot Bert Hinkler captured the imagination of several generations of Australians and Britons, in a similar fashion to Charles A. Lindbergh, especially after an engineer climbed onto a wing in mid-flight to restart a stalled engine.

The success of the artificial reef of aircraft, lowered off Bang Tao beach last year, indicates that there is a great interest in diving on wrecks of different kinds.

Australia is also the nation that currently delivers the largest number of tourists to Phuket.

Agency reports say the ''smoking gun'' backing the filmmaker's finding is the unique design of the 'Lady Southern Cross', a Lockheed Altair.

Details of the plane recorded in sonar imaging matched that of the Altair, Mr Lay told reporters at a news conference.

''The Altair itself is a very unique aircraft, there were, I think, only four Altairs built,'' he said.

''If it is a Lockheed Altair it wouldn't be anything other than the 'Lady Southern Cross' and the aircraft flown by Kingsford Smith.''

Mr Lay said the plane's state of preservation, as a result of it being covered in mud, meant the remains of Sir Charles and Mr Pethybridge might also be found.

The filmmaker said he would now seek confirmation that the wreck is an Altair from Lockheed in Australia and the United States.

He plans to mount a recovery operation in November this year.

The one problem with diving on the aircraft would be the need to pay a fee to the repressive junta that rules Burma, an ethical issue that has failed to deter some divers from visiting other remote offshore islands and reefs.