Missing teens found in 'Christmas miracle'

The two 18-year-old men and two women, 18 and 19, were found on Swan Island off the Bellarine Peninsula about 9am on Tuesday after they got caught in strong easterly winds and spent the night drifting in a choppy Port Phillip Bay.

Having just completed their final school exams, they went to Rosebud for an end-of-year celebration and set off on two inflatable paddle boards on Monday evening.

But they drifted into the middle of the bay, ultimately ending up more than 20 kilometres away.

Cold and disoriented when they washed up about 2am on Tuesday, they found shelter in a hut.

Once the sun rose, they wandered Swan Island before being found by security officers.

The group were reunited with family at Geelong Hospital, where they underwent precautionary health checks.

All four were in stable conditions with no obvious injuries, according to Ambulance Victoria.

Island security and military personnel ultimately alerted police to their presence on Tuesday morning.

"All too often, these things usually end in tragedy," Acting Inspector Ian Pregnell told Melbourne radio 3AW.

"This is, one might say, a Christmas miracle."

Jack Shi, father of one of the teens, told Nine News of his and the other parents' relief.

"We're very, very happy about that. It's huge, huge relief. We were very desperate," he said.

Swan Island is a military training base on one side, with Queenscliff Golf Club on the other.

It has a long history of military use, with a fort originally established to protect Port Phillip Bay from potential Russian invasion in the 1870s.

During World War I it was used as a depot for naval mines before becoming a training base following World War II.

A spokesperson for Defence confirmed their members provided assistance to emergency services in the rescue of four civilians but directed any further enquiries to Victoria Police.

Winds in the area were easterly and southeasterly on Monday evening and overnight, and 20-30km/h, according to the Bureau of Meteorology.

However at South Channel Island - a close observation point - they reached 30-40km/h.

Local diving tour operator James Murphy told AAP it was not unusual for people to be swept from one side of the bay to the other, and he had personally rescued kayakers in a similar situation three years ago.

He said Swan Island looked like a typical beach so the group may not have realised it was a military base when they arrived.

"We've been lucky in this instance that everybody survived," according to Mr Murphy, the director of See All Dolphins Swims.

"It's a really humbling reminder that the environment needs to be respected and if you are unsure, please reach out to the local lifesavers, talk to local tour operators or people that understand that environment."

The group's belongings including phones and IDs were found on the beach by a passerby about 8pm on Monday, triggering the search.

The effort was called off about 4am due to deteriorating conditions but resumed at first light.

The successful rescue came a day after a couple was found safe and well in the Grampians in Victoria's west after their car became bogged at the weekend.

Australian Associated Press