A black box locator is about to be loaded onto an Australian navy ship and sent out with the search effort for the missing Malaysia Airlines plane.

Prime Minister Tony Abbott told reporters on Saturday morning the black box recovery equipment was to be put on a ship in Perth.

“It will be taken to the most prospective search area and if there is good reason to deploy it, it will be deployed,” he said in Sydney.

He said no debris had been recovered despite the number of vessels in the updated search area.

“We should not underestimate the difficulty of this work,” he said.

“These are inhospitable seas. We are trying to find small bits of wreckage in a vast ocean.”

New Zealand Air Vice-Marshal Kevin Short told media on Saturday a cluster of 11 white rectangular objects was sitting just below the surface about 1600 kilometres west of Perth.

“It’s hard to identify because all you’re seeing is this one-metre rectangular piece of material.”

The search area west of Perth shifted north on Friday after the likely path of MH370 was updated.

Five aircraft also spotted debris in the ocean on Friday.

But the Australian Maritime Safety Authority (AMSA) warns the objects cannot be verified as linked to the Malaysia Airlines flight until they are picked up by ships.

Authorities say weather conditions for Saturday’s search are favourable but expected to deteriorate in the afternoon.

Eight aircraft and six ships are involved in the search.

The plane carrying 239 people, including six Australians and two New Zealanders, disappeared on March 8.