A dive team inspecting the 170-tonne wreck spent hours searching for the damaged metal remnants, combing through masses of thick seaweed at the base of the eastern break wall.

The $5 million wave-to-energy barge, one of the first of its kind in the world, sank below the surface of the water over the weekend after heavy seas tore it from its moorings on Friday and swept it into the rock wall.

Hope Diving Services managing director Anthony Hopewell said the company was called in to locate the device after a marine surveyor failed to find it.

"It's smashed to pieces; there's a lot of loose marine growth up against the wall, which makes it difficult to find," Mr Hopewell said.

"The salvage will be picking up pieces - it's not like you can refloat it and bring it back to shore."

Divers attached marker buoys to the two largest pieces to track the wreck should it move with the tides.

Mr Hopewell said the stricken device was beyond repair.

Divers also inspected pylons 150m off shore to determine how the barge snapped from its moorings.

Oceanlinx spokesman Colin Parbery said engineers and the project's insurers met with the Port Kembla Port Corporation yesterday to "formulate a way forward".

The barge was at the forefront of renewable marine technology and had fed power back to the Integral Energy grid since March this year.

The device converted wave energy into air pressure to turn a wind turbine.

Last year Oceanlinx won a $3 million Climate Ready federal grant to help develop the device, all of which had been allocated.