Australian police seized the country’s largest haul of cocaine aboard a fishing boat that had broken down near the coast of Queensland, arresting 13 people alleged to be part of a drug-smuggling syndicate.

Authorities tracked a recreational fishing boat as it traveled out to sea where it allegedly met a mothership in international waters to fetch the cocaine – some 2.34 metric tons with a street value of nearly half a billion dollars.

The boat suffered a suspected mechanical breakdown, leaving the alleged traffickers stranded 18 kilometers (11 miles) off the northeastern tip of K’gari island, formerly known as Fraser Island, on Saturday.

Police seized their chance to board the boat, arresting two men at sea in a joint investigation between federal and local forces. Another 11 were arrested on shore, including two juveniles.

The arrests include the Brisbane vice president of the Comanchero Outlaw Motorcycle Gang, which is accused of engaging in violence, extortion and trafficking, police said.

All the suspects are accused of being part of a criminal syndicate and have been charged with conspiracy to import a commercial quantity of drugs. The maximum penalty is life imprisonment.

Police said the haul was the equivalent to 11.7 million individual street deals.

“We know that criminals go to extreme lengths, and often risk their own lives, to smuggle drugs into Australia with no regard to the harm they cause to Australian communities,” Commander Stephen Jay said.

“This alleged attempt to collect more than 2 tons of cocaine from the ocean shows that criminals will do anything for their own greed and profit.”

The police operation began in November following a tip-off that the Comanchero biker gang was allegedly planning to bring the drugs into the country.

Australian police have warned in recent years that international drugs cartels are increasingly targeting the country, where a surge in cocaine use combined with some of the highest street prices in the world has fueled a lucrative illicit market.

Last week, six so-called “narco subs” stuffed with cocaine were captured in a Colombian-led international anti-drug operation. Among the haul was 225 metric tons of cocaine, 5 tons of which was found aboard a semi-submersible vessel plying a marine trafficking route from Colombia to Australia, according to the Colombian Navy.