One of the Navy's largest ships, HMAS Canberra, may need to be taken out of the water to fix a problem with its propulsion system, the Navy Chief told a Senate estimates hearing in Canberra.
"Our aim is to resolve it early in the piece of this ship's life so that we actually have the expected 25 to 30 year life of the ships," Vice Admiral Tim Barrett said.
"The POD sits below the hull of the ship, there is less machinery internal to the ship, in terms of the engines, so it may need to be dry docked."
Defence also confirmed it was investigating whether the same problem was affecting HMAS Adelaide.
The two ships are part of the Navy's Canberra-class Landing Helicopter Dock (LHD) ships. The 230-metre long, 27,000 tonne ships only entered service in the last few years.
Their propulsion systems include a gas generator, two diesel generators and two Siemens POD azimuth units, according to the Navy.
The two ships have been unable to join Cyclone Debbie recovery efforts, although Defence officials pointed out to senators that HMAS Choules is the on-call ship and is currently headed to the Queensland coast.
They said HMAS Canberra is currently in Sydney being investigated by divers and are unable to say when the ship will be repaired.
