There are calls for louder shark warning sirens, after a “very stubborn” Great White shark was herded away from close to 150 surfers at Middleton Point and some beach users remained none the wiser.

The Westpac Lifesaver Rescue Helicopter Adelaide reported the incident via its Facebook page, saying that the helicopter encountered the shark on Sunday afternoon (10 January).

According to the post, it took the crew 30 minutes, with support from other Surf Life Saving assets, to herd the shark safely out to sea. 

The post also issued a reminder to beach users to listen out for the warning siren and act quickly.

“Please remember, if you hear the warning siren exit the water as quickly and calmly as possible,” it said.

In the water at the time were close to 150 surfers, as estimated by the crew, and the beach was also busy, but some social media users have suggested they weren’t aware of the problem.

One user commented: “Could hardly hear it, in fact we were wondering when will they turn the siren on!!”

A second responded with, “I agree, as I was on the beach and it was very hard to hear and it didn’t go for long”.

Shark activity increases in warmer months due to the migration of fish into the St Vincent Gulf.

Fleurieu beaches are patrolled over the summer period by both the Westpac Rescue Helicopter and a fixed wing shark-spotting aircraft.