Senior constable Gene Hill said police rushed to save the wallaby, dubbed "Dawny", after locals reported her struggling out at sea.

"Water police officers jumped into action and arrived on scene, observing a very fatigued marsupial swimming in circles," he said.

"Officers promptly conducted person overboard drills and a very relieved wallaby was assisted from the water.

"A passenger safety briefing was conducted and water police skipped across the bay, transporting the female wallaby ... to the safe haven of North Stradbroke Island."

Constable Hill said Dawny was given a ride back to dry land where she was released into the wild to swim another day.

Rumour had it she was training for the Olympics in Tokyo later this year.