The Royal Australian Navy has found four unexploded bombs that were dropped onto the Great Barrier Reef during a military exercise off central Queensland last month.

The bombs were dumped by two US fighter jets during Exercise Talisman Sabre at Shoalwater Bay in mid July.

The Navy's mine hunting vessel HMAS Gascoyne found the bombs today and is working out a plan to retrieve the ordnance.

The Navy says the bombs were detected at a depth of 60 to 70 metres using sonar equipment in a remote-control submersible.

It says it is working with the US Navy to recover the bombs.

Officials say the jettisoned ordnance has never posed any sort of safety or environmental threat.

The timing of the US-led recovery operation now depends on the weather.