3 people had to be rescued from their 30-foot inflatable catamaran after sharks attacked the boat, officials say

• Three people were rescued from their inflatable vessel after sharks attacked its hull, officials said.
• The trio were around 510 miles off Australia's northeastern coast, according to rescue authorities.

Three men on board an inflatable catamaran were rescued off Australia's northeastern coast on Wednesday after their vessel was attacked several times by sharks.

The trio — two Russians and one French citizen — were about 510 miles from shore when Australian authorities picked up their distress alert in the early morning, the Australian Maritime Safety Authority said in a statement.

The Russian vessel had departed from the Pacific archipelago of Vanuatu and was heading to the city of Cairns in Queensland, the AMSA said.

Both hulls of their 30-foot catamaran "have been damaged following several shark attacks," authorities added.

Officials said they asked a nearby Panama-flagged ship, the Dugong Ace, to help rescue the three people. A Challenger rescue aircraft was also sent to assist from Cairns.

When found, the catamaran had "large sections of its hull missing," AMSA Response Centre manager Joe Zeller said.

"There's many reasons that vessels are attacked by sharks. However, the motivations of these sharks is unclear," Zeller said.

Footage shot by a Challenger rescue plane shows the state of the vessel when rescuers arrived.

The three sailors are aged between 28 and 64, in healthy condition, and on board the Dugong Ace on their way to Brisbane, Zeller said. Their full trip would likely have taken between two to three weeks, he said.

"The emergency beacon absolutely saved their lives," Zeller added. "It enabled the rescue coordination center to identify their precise location and empower the most appropriate and quickest response to rescue them."

The trio are expected to arrive in Brisbane on Thursday, the AMSA said in its statement.

Sharks and orcas have been making headlines this summer amid a rising number of reports documenting attacks on vessels. But it's still unclear what causes these encounters, or if they are related at all.