The Australian Maritime Safety Authority said it responded to an alert from an emergency beacon.
When rescuers arrived at the scene more than 500 miles east of the Australian coast in the Coral Sea, they found both hulls of the men’s 30-foot boat had been damaged after several shark attacks.
The agency enlisted the help of a Panamanian-flagged ship, the vehicle-carrying Dugong Ace, which was able to complete the rescue and take the two Russians and one Frenchman aboard. A rescue plane also flew to the scene.
“The three males were very happy to be rescued, and they’re all healthy and well,” said Joe Zeller, duty manager at the agency’s Canberra response centre.
The men, aged between 28 and 64, are due to arrive in the Australian city of Brisbane on Thursday.
Mr Zeller said a journey from the Pacific Island nation of Vanuatu to Australia on such a vessel would usually take two to three weeks.
Aerial photos showed major damage to the catamaran, with the front section of one hull completely missing.
Mr Zeller said the GPS-encoded emergency beacon had saved the men’s lives by allowing rescuers to quickly pinpoint their location and mount an appropriate rescue.
He said there were many reasons why a shark may attack a boat.
“However, the motivations of these sharks is unclear,” Mr Zeller said.