You could be forgiven for thinking it was an aquarium, but this is the pool stunned swimmers shared with a shark.

Jennifer Hill was blissfully unaware the dusky whaler shark was lurking below while she took her morning dip in the rockpool in Sydney's Palm Beach.

After giving her photographer friend a heads up to snap up a storm, she alerted a marine rescue team to pull the juvenile shark from harm’s way.

Swimmers were blissfully unaware the dusky whaler shark was lurking below while they did their morning laps

The juvenile shark was found in the the rockpool in Sydney's Palm Beach

Ms Hill told Daily Mail Australia she was doing laps in the pool for more than an hour.

‘It obviously it wasn’t very hungry because it had plenty of opportunities to take a bite.'

She was only alerted by shocked tourists when she stepped outside to dry off.

Photographer Rita Kluge lost no time racing down to seize the moment - which was the first time she had seen a shark in the popular swimming spot.

‘I don’t know how it got in the pool but I have never seen one there before. It’s very unlikely,’ she told Daily Mail Australia.

'I wanted to jump in but I wasn’t allowed so I just took pictures from the steps.’

Jennifer Hill said she was swimming for an hour before she discovered she was sharing the pool with a shark

The popular swimming spot was plunged into lockdown until they rescued the shark

It is unclear how the shark found its way into the water

Images show Manly Sea Life Sanctuary workers rescuing the shark and releasing it into the nearby shore about 2.30 pm.

They said the young dusky pup posed no threat to humans.

However, mature dusky sharks can grow up to 3.65 metres and have been known to attack humans in self-defence.

You can see more of Rita's marine photography here

The shark was released into the nearby shore about 2.30 pm