Many thought the tsunami warning eventuated into nothing. However for Jim Yiannaros, Director at Batemans Bay Oysters and coordinator of the Clyde River quality insurance program, this is because their image of tsunami isn't quite accurate.

"Everyone thinks a tsunami is just one big wave that just rolls in, but it's an ongoing process," he said. "The tides are still surging now as we speak."

Mr Yiannaros describes the effects of the tsunami as like lifting up a kids plastic swimming pool filled with water and dropping one end. The water sloshes from side to side and takes a long time to settle.

"That is what the tsunami is doing to us now," he said.

"It doesn't matter what the tides are doing. This isn't tides. This overpowers tides."

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On a usual day, Mr Yiannaros said low tide would be .3 metres, flowing in to hightide at 1.5 metres over a period of three hours.

Due to the tsunami, the Clyde river is draining to .3 metres then filling to as high as 1.9 metres in the space of 15 minutes.

Mr Yiannaros said the tide has been rising two feet in ten minutes, creating powerful water flows.

"The current was that strong," he said. "The water was running that fast. All our infrastructure and baskets up the river were impacted big time."

Rising tides collect logs and other debris from the shore and sweep it along with the current. This debris gets hooked onto oyster farm lines.

"It doesn't matter how strong your lines are, if they're covered in debris, everything is ripped out," he said.

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Mr Yiannaros estimates more than 80,000 oyster baskets have been ripped off their lines along the river, but he stresses the extent of the damage is still unknown.

"The salvage isn't over yet," he said. "We are still counting."

"It will easily be six to seven weeks of maintenance and repair - maybe more."

The wet season over summer has caused changes in water salinity preventing Batemans Bay Oysters from harvesting. Mr Yiannaros said the company had been stockpiling oysters waiting for ideal harvesting conditions. These stockpiled oysters have all been tipped over in the surging waters.

The company lost 6000 dozen trays of oysters to the bottom of the river, most probably washed away and irretrievable.

However, the movement of river currents means some oyster leases were heavily damaged, while others were completely untouched by the impact of the tsunami.

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"The impact of this tsunami is bigger than the last tsunami in Japan [in 2011] and the boxing day tsunami [in the Indian Ocean in 2004]," Mr Yiannaros said.

"After those events it was five to six days before waters returned to normal. We are hoping it's the same this time around."