A teenager has narrowly escaped being bitten by a shark after it attacked his surf ski during a race off Seacliff, in Adelaide's south.
Nat Drummond, 19, was one of about 70 competitors racing from Seacliff to Grange for a surf ski race when he was pushed off his ski about 11:15am on Sunday.
The shark, which may have been up to 3 metres long, attacked the front of the paddler's ski and ripped a chunk out of the bottom.
South Australian Ocean and Surf Ski Paddlers race director Craig Burton said Drummond's peers quickly responded to the incident and he was able to walk away uninjured.
"All the paddlers in this event are surf lifesavers," he said.
"When something like this happens, they turn into rescue mode and it was fantastic the way they got him onto their surf skis and safely returned him to shore.
"[Nat's] in quite good spirits at the moment. We've got a lot of support thrown around him and his family."
Mr Burton said while shark sightings were not unusual in Adelaide in spring, he had never seen an attack during a competition.
"I've personally been doing this for well over 40 years and I do know some of our paddlers have seen sharks while out paddling, but never anything like this," he said.
"Where we are at Seacliff, it's quite shallow, there's reefs and it was low tide, perhaps that could've had something to do with it."
Shark could not be found
A Surf Life Saving SA helicopter searched for the shark but was unable to locate it after the incident.
The beach has been cleared of any danger and people have returned to the water.
Mr Burton said it was a timely reminder for the public to be vigilant in the ocean as summer approached.
"The mark was around [Nat's] leg area so if it was on another angle, it might've been a different story," he said.
"We all know that there are sharks out in the ocean; obviously the further you go out the more likely they'll be there.
"[It's] just something to be aware of, but Surf Life Saving SA has good measures to try and minimise the risk with patrols all weekends and over summer."