Gutted Eirian Evans’ cherished ring slipped off his finger during a diving expedition with his new bride, Bethan, off Green Island, Cairns.
The couple, both 29, begged tour staff to dive down to find it but after scouring the world-famous coral system for several hours they gave up.
Eirian and Bethan were forced to return home without the precious silver ring – but left their contact details with the scuba school.
They flew back to Britain but days later Eirian got an email in the middle of the night telling him the ring had miraculously been found – and was on its way back to the UK.
A sightseer enjoying the same snorkelling expedition several days later had been inspecting the seabed when he spotted the ring lodged in coral.
He handed it over to staff at the Ocean Free diving school who found Eirian’s contact details and sent it back to the relieved couple.
Eirian, of Cardiff, said: “Because the ring was new and I’m not used to wearing rings, I had been playing with it non-stop since our wedding day.
“I got out of the sea and went to fiddle with it and realised it had gone. I was absolutely gutted as I thought I’d lost it forever.
“When we got back on the boat and said it was missing, two of the scuba divers offered to go and look for it but they couldn’t find it.
“They asked me to leave my contact details with them but I thought they were humouring me. I was convinced I would never see it again
“I was absolutely gobsmacked when I got the email from the diving company saying someone had found it. I couldn’t believe it.”
Eirian and Bethan met during a night out in their local rugby club when they were 21 and he proposed last October.
The pair got married on June 15 before setting off on their dream honeymoon to Australia.
The lovebirds spent two weeks travelling and sightseeing on the east coast before staying in Melbourne to watch the British and Irish Lions rugby tour.
But the highlight of their trip was seeing the Great Barrier Reef, one of the seven wonders of the world, composed of 2,900 individual reefs and 900 islands.
The natural wonder covers 344,400 square kilometres – and is so vast it can be seen from outer space.
Rugby-mad Eirian, a claims handler for Barclaycard, said: “The wedding day was amazing. I was buzzing the whole time and Beth looked incredible.
“The trip to Australia was the trip of a lifetime. Coming back without the ring was heartbreaking but getting it back like this is the icing on the cake.”
Eirian’s wedding band arrived safely in the post and is now back on his finger – much to accountant Bethan’s delight.
She added: “I was so shocked and relieved when we found out someone had found it.”
Taryn Agiun, co-owner of Ocean Free, said her staff were thrilled when the prized item was brought to the surface by one of their customers.
She said: “We all got tingles when we found out it was a wedding ring and could possibly belong to someone who had gone on one of our tours.
“It obviously has a huge amount of sentimental value to the couple. It’s such a fantastic story.
“It’s a beautiful omen to their marriage, which I think shows they are meant to be together forever.
“It’s truly amazing the ring survived, especially because fish often eat shiny or sparkly objects mistakenly for food.”