A SEMI-BURIED aircraft engine believed to date back to the Second World War (WW2) was the last thing Hayman Island State School Principal Rohan Robertson expected to find on an evening boat trip with his family last month.

Mr Robertson, who is hesitant to divulge the exact location of the find, only exposed at very low tides, immediately notified the Great Barrier Reef Marine Park Authority (GBRMPA) and the Royal Australian Air Force (RAAF), who advised him that to their knowledge it had not been reported previously.

"The RAAF believe that it is an engine from [the] World War 2 (WW2) period and that it could be linked to [an] RAAF Beaufort Bomber, which went missing with four personnel, without trace, in WW2," he said.

Mr Robertson said this 'long shot' was only one of many possibilities.

He said this particular type of radial Pratt and Whitney engine was also used by Catalinas, "however, the RAAF historian involved in the investigation believes there are no reports of missing, lost [or] crashed Catalinas in this area both in war time and post war".

Catalinas may have been used in the early days of the Hayman Island resort, though Mr Robertson says there is no knowledge of one crashing in local 'folk law'.

"Local folk law does however tell of a US Navy plane, possibly a 'Wildcat' or 'Hellcat' from a carrier, crash landing in the area, while preparing for battle in the Coral Sea," he said.

"As it happens, the engine used by these planes was also a Pratt and Whitley, which was quite common for a number of planes in that era."

Mr Robertson said this particular plane wreck was never found.

He said there was some evidence to suggest that the engine he and his family found had been moved from its original 'sea grave', possibly for the removal of the propeller.

Mr Robertson is now seeking any information that may assist in identifying the engine and its plane.

He can be contacted via email to rlrob0@eq.edu.au.