Four teenagers have been found alive in what police have hailed a “Christmas miracle” after going missing in waters off Victoria’s Mornington Peninsula.

Two 18-year-old men and two women aged 18 and 19 were found across the bay on Swan Island off the Bellarine Peninsula about 9am on Tuesday.

They were taken to Geelong Hospital in stable conditions with no obvious injuries, Ambulance Victoria said.

The group were using two inflatable paddle boards off Rosebud Beach on Monday – about 30km away from where they were found.

They were swept by the tide, wind and current from Rosebud, straight across Port Phillip Bay to the Queenscliff area, Victoria Police Acting Superintendent Terence Rowlands said. 

The group were found on a Swan Island beach, with island security and military personnel ultimately alerting police to their discovery.

“You can see the smile on my face – (it’s) absolutely sensational that they’ve been found safe and well,” Supt Rowlands told reporters.

“Luck has had a lot to do with it.” 

The teenagers were cold but very thankful to be on dry land when they were found.

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

“This is, one might say, a Christmas miracle.” 

It was an emotional time when families were told the teenagers’ were found, he said. 

Father Jack Shi told Nine News the parents were relieved their kids were safe.

“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 and the Queenscliff Golf Club is on the other.

It has a long history of military use and a fort was originally established on the island to protect the entrance to 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 area since World War II. 

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

The hunt for the teenagers was called off about 4am on Tuesday because of deteriorating conditions, before resuming at first light. 

A man who said he was the father of one of the boys told Seven’s Sunrise program earlier on Tuesday the teens had just completed their final school exams and went to Rosebud for an end-of-year celebration.

A couple were found safe and well in the Grampians in Victoria’s west on Monday after their car became bogged.