A cargo ship hired to replace Australia's out-of-action $528 million icebreaker Nuyina has suffered minor damage after running aground in Antarctica.
The Happy Diamond was grounded on a shoal off Mawson Station about 7.30pm (AEDT) on Sunday for about an hour.
No one was injured.
"Minor damage occurred to a ballast water tank," an Australian Antarctic Division (AAD) spokeswoman said in a statement.
"The vessel's operator ... has assessed that there is no danger posed to personnel, the vessel or the environment.
"Ongoing monitoring and assessments will continue."
The Happy Diamond is returning to Hobart as scheduled and will undergo repairs.
The AAD chartered the vessel after Nuyina was forced to miss the resupply season because it needed maintenance.
The Nuyina, which was plagued by delays during construction, was due to return from Singapore to Australia in March but is now expected to return in April.
It was revealed in July that shaft couplings on the ship needed to be replaced after an "unexpected issue" was discovered.
Nuyina's maiden voyage to Antarctica in December 2021 was pushed back due to issues with its alarm and monitoring system.
The AAD says the Happy Diamond incident will be reported and investigated by its operator, Big Lift Shipping BV, in co-operation with the Australian Maritime Safety Authority.
It had earlier completed resupply efforts at Australia's Casey and Davis stations in Antarctica and was in the final stages of resupply operations at Mawson.
A second AAD-chartered ship, icebreaker Aiviq, escorted the Happy Diamond through sea ice to open water.
It is the second time Happy Diamond has run into trouble during fill-in operations.
In November, it was forced to return to Hobart while on a re-supply mission due to mechanical problems.
Once it returns to Australia, Nuyina will require time for commissioning as it prepares to serve the nation's Antarctic and Southern Ocean science efforts, the AAD says.
