This article is more than 2 years old

This article is more than 2 years old

A great white shark swimming in one of Australia’s most renowned shark habitats interrupted a police operation on Saturday by serenely terrifying the officers.

The shark, dubbed Noah by South Australia police, glided in between a police dinghy containing two life-jacketed police officers and their intended target, a recreational fishing boat selected for a random breath test.

It was about 4.5 metres (15ft) long – longer than the inflatable dinghy – and swam after the small boat before circling back to the 5.7-metre fishing boat that it had been following for the previous 10 minutes.

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“Police were concentrating on recreational boats and checking registration, licences and safety equipment along with alcohol and drug-testing operators when they were paid a visit by one of the locals,” SA police wrote on social media. “Noah wasn’t keen on being breath tested and our Water Operations Unit officers were happy to oblige!”

One of the men on the recreational fishing boat told ABC radio in Adelaide that they had been trying to escape the shark when police approached.

“We kind of had thoughts of changing our Bonds [underwear] a couple of times,” Mark Oates told the ABC. “So we powered up and cruised out of there but it just kept following us for 10 minutes.”

The SA police patrol boat Investigator II was also in the area, about nine nautical miles east of Edithburgh on the Yorke Peninsula in the Spencer Gulf. Neptune Island, a global hotspot for great white sharks, was about 30 miles (50km) west.

Oates said he saw two police approaching in the inflatable dinghy.

“I told the boys to back off a bit because the shark was right next to us,” he said. “For probably the next 10 or 15 minutes we just sat around … there was very little fish caught that day, I can tell you.”

Attempts to breath-test Oates and his companions were also abandoned.

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“I don’t think they were quite that game to come up close to us by that stage,” he told the ABC.

Great white sharks are listed as vulnerable under Australian law and cannot be harmed without an exemption granted by the federal environment minister.

There are no firm population estimates of the migratory species, which can travel up to 4,000km in the open ocean, but CSIRO researchers this year used a genetic analysis to determine there were at least 5,500 individuals swimming in waters off Australia’s east coast and about 1,500 living off the west coast.