Three men were plucked to safety Wednesday after sharks started tearing chunks from their inflatable catamaran as they attempted to sail to Australia.

The men -- two Russians and a French citizen -- were picked up by a cargo ship while floating in the shark-filled Coral Sea some 800 kilometres (490 miles) southeast of Cairns.

"Both hulls of the vessel have been damaged following several shark attacks," the Australian Maritime Safety Authority said in a statement.

The authority said the trio had planned to sail from the Pacific archipelago of Vanuatu to the city of Cairns in tropical northern Australia, a distance of more than 2,000 kilometres (1,200 miles).

They activated an emergency distress beacon in the early hours of Wednesday morning.

Footage shot by a rescue helicopter shows the catamaran bobbing in calm seas as it is approached by the hulking Dugong Ace, a vehicle transporter that came to the sailors' aid.

The Coral Sea is brimming with reef sharks and other apex species such as tuna and marlin.

According to the Australian government, it is home to more sharks "than almost any other survey site in the world".