Charlotte Kirwan and her partner, Logan McCann, were walking along the boardwalk about 12.30pm in the hopes of spotting one of the grey nurse sharks that frequent the waters there.

Instead, they were drawn to a young family pointing at a section of water where small fish were starting to surface.

"There were lots and lots of fish coming up, then up popped a penguin," Ms Kirwan said.

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"We were so shocked and I started screaming to my partner as he wasn't looking.

"The penguin kept diving down and resurfacing swimming in a loop in our view."

As the crowd of onlookers swelled to about 15, Mr McCann took out his phone to capture the encounter before it swam off.

Ms Kirwan said she couldn't be sure but there appeared to be a second penguin hiding under the dock.

Last month a local couple walking their dog spotted a penguin swimming in Wollongong Harbour.

At the time, Rescue and rehabilitation coordinator for the South Coast branch of Australian Seabird Rescue Lisa Hood told the Mercury it was not unusual to see Little Penguins in Wollongong.

She said there was a colony on an island off Port Kembla where the penguins bred.

"It is not overly unusual to see a penguin go into the harbour, they go into Kiama harbour all the time," Ms Hood said.

Ms Hood said penguins had likely had a rough couple of weeks with the rain and big waves, burrows might have flooded or it could have been following fish into the harbour.

Ms Hood stressed the importance of people not touching penguins if they saw them in the harbour, in the water or on beaches.

"If you see one, don't touch it, call us and keep your dogs away from it. Observe it from a distance, and we will send someone out immediately," she said.

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