RMS maritime division executive director Angus Mitchell, in Port Stephens on Tuesday to oversee clean-up efforts, said the rough sea conditions made locating the shipping containers “impossible”.

“Whilst they’re floating they are a significant danger to navigation, which is why we’re putting out marine notices and hourly warnings,” he said.

“We’ve only had reports of four sighted. It’s very difficult to track them and in these conditions, it’s impossible to find them.

“They’re either sitting just below the surface where you’ll never see them or very best case they’re just above the surface.”

Beaches in Port Stephens and Tea Gardens-Hawks Nest have so far copped the brunt of the debris. It comes after 83 shipping containers fell from Libyan-registered container ship YM Efficiency in rough seas on June 1.

Car bumper bars, printer cartridges, plastic cups, containers, wooden bowls, lollies, chips, cookies, nappies, packaged food and drinks and analogue clocks have washed up on beaches.

Approximately 20 skips bins of waste have been recovered so far. 

Four containers were reported to have been seen on Saturday afternoon off Hawks Nest, near Cabbage Tree Island.

Port Stephens Marine Rescue operations officer Tony O’Donnell said the organisation was advising boaters to remain cautious and vigilant.

“We’re warning all ships between Port Stephens and Forster to keep their eye out,” he said.

“Depending on speed and if you have a keel, if you hit one of these containers, you will have a major problem.

“Remain really vigilant.”

Skippers are encourage to report container sightings to RMS on 13 12 36.

Volunteers rally to clean Port’s beaches of container debris | photos, videos

Shipping container clean up, beaches littered with debris | photos