One of four teens who were swept to sea on frigid Victorian waters says he feared he would close his eyes and “I might not open them again”.

The friends drifted through the cold night in Port Phillip Bay, unable to direct their inflatable paddle boards which were at the mercy of the strong wind and tide.

As temperatures dropped and the light faded, the two males and two females, aged 18 and 19, tried to stay calm as they attempted, and failed, to head for lighthouses along the coast.

With their two paddle boards bound together, they began to lose hope as rescuers in the air and on the water did not see them on Monday night.

“There was a point that it was really hard, because we could see the helicopters and boats searching for us,” Rong Shi told the ABC from his hospital bed.

“The helicopters got really close to us, but they didn’t find us … we were losing our hopes.”

Mr Shi said after many hours they became extremely tired as they tried to endure the icy conditions; at one point two of them fell into the water.

“When I closed my eyes, I felt like I couldn’t feel my hands … if I closed my eyes I might not open them again,” he told the ABC.

Mr Shi said he realised it “might be my last chance to hustle, so I just, yeah, wanna stay alive.

“That’s all we had to do, keep our energy, stay warm.”

Rong Shi speaks from his hospital bed. Photo: ABC screenshot

Miraculously, the boys washed up on Swan Island at about 2am Tuesday, some 20km from where they set off at Rosebud, a seaside town on the Mornington Peninsula.

The island is home to a top secret military training base that is shrouded in secrecy.

The base has 24-hour security and only those with special clearance are permitted to enter it through a security gate.

The facility was created in the 1870s as a safeguard against the threat of a possible Russian invasion during the Crimean War.

It was used to store explosives during World War I and became a base after World War II.

The eastern side of the island is occupied by Defence while the western side is home to a golf club and yacht club, however only members are allowed to visit.

Swan Island as seen from Queenscliff, Victoria. Photo: AAP

Mr Shi said the group at first took refuge under a tree but it was so cold they went in search of shelter and discovered a storage hut.

They huddled together for the rest of the night and in the morning went looking for help, he told the ABC.

With great relief, they were rescued by island security guards who wrapped them in blankets and offered protein bars, cookies and hot tea.

The survivors thanked everyone who joined the rescue effort, including taxpayers.

“It still feels like a dream to me … I can’t believe we made it,” said Mr Shi.

“If you look back, it’s really, it’s a miracle, a stand-up paddle, 30 kilometres.”

-with AAP