Beach reopens following sightings of sharks, including a Great White shark!

Lifeguards closed Thirroul Beach after wakeboarders spotted three sharks yesterday.

The sharks, estimated at 1.2m long, were spotted 300m offshore about 1pm.

After closing the beach, lifeguards conducted a grid search of the water using a jet ski from Stanwell Park and reopened the beach about 2pm.

Wollongong City Council spokesman Jason Foye said swimmers were kept aware of the threat and warning signs were put in place.

He said the jet skis were used not only to search the area but also to ward off any unwanted visitors.

"We use the jet ski as a control measure. The vibrations under the water do tend to send (sharks) away from the area," he said.

He said lifeguards continually monitored the beach from elevated positions "so they can maintain surveillance not only in the designated swimming area but up and down the beach".

It was the second shark sighting at Thirroul Beach this year.

Surfers said they saw a great white between 2.5m and 3.5m long on January 14.

"It sort of jumped up out of the water right next to one of the other guys, had a look around and then dived down and swam off," surfer Keith Fennell said at the time.

The latest incident is one of a string of shark sightings on Illawarra beaches this summer.

Sharks have been seen at Thirroul, Corrimal, Windang, Warilla, North Wollongong and Blacks beaches.

Twenty-four-year-old Steven Fogarty also suffered 40 puncture wounds to his right calf and cuts to his fist when he was attacked by a shark in Lake Illawarra on January 12.