Image copyright Christina Tham Image caption Tham won two gold medals in underwater hockey

It was a 38-year wait - but the hard work paid off for Christina Tham at the Southeast Asian (SEA) Games in the Philippines this week.

Tham first represented Singapore at the SEA Games - a regional Olympic-style event - in 1981, winning silver in swimming at the age of 12.

Now aged 50, she returned to the games and finally went one better.

Tham won not one, but two gold medals in underwater hockey - a sport making its debut in the games.

"I never thought I would be back [at the] SEA Games and winning golds and scoring goals," she said.

"I never thought I could perform at this level again."

Image copyright Christina Tham Image caption Tham decided to get back into professional competition in 2005

Tham got into swimming aged seven, when her father had a near-miss while canoeing on a lake during a family trip to Malaysia.

Her father, who was in his late 40s, could not swim and initially resisted wearing a life jacket - but relented on her mother's insistence.

"I remember I was in another canoe across the lake when I heard a loud shrill," Tham told the BBC. "I saw my dad floating on the water, held up by the life jacket. That saved his life."

After her dad was rescued, he quickly signed up the whole family for swimming lessons - and Tham hasn't stopped swimming since.

At the age of 12, she represented Singapore at the 1981 SEA Games in Manila, claiming her first silver in the 4 x 100m medley relay.

The SEA Games, which are held every two years, sees athletes from the region compete in a variety of events.

"I was very young and didn't appreciate the significance [of my] achievement. I come from a typical Singaporean Chinese family where [you're] expected to [accept] achievements with modesty," she says.

"It was only after I became an adult that I realised the enormity of my achievements - I was 12 and had won a medal in the SEA Games and was in the top 10% in the country in the [national examinations that year]."

Two years later, she was back at the SEA Games, clinching another silver in the 200m breaststroke.

But that's where her journey as an athlete stopped - at least for the next three decades or so.

Image copyright Christina Tham Image caption Tham (fifth from right) and her team

Tham pursued a career in the legal industry, training as a solicitor and eventually heading up her own section of a legal department within a real estate company.

It wasn't until 2005 that her sporting career resumed - and it started with a story in a newspaper.

"I saw an article [about underwater hockey]. It sounded so interesting and intriguing, [so I] went to try it out," she said.

"I thought that playing a team sport would really round me up as a person. I found I missed a dimension doing only solitary sports my whole life."

The high-speed game, which involves a heavy underwater puck, was added to the SEA Games this year. And so, 38 years after her debut, Tham found herself back where it all began - the Philippines.

She scored two goals - one in a 4 v 4 event and one in a 6 v 6 event - as the Singapore team won both golds.

And Tham has no plans to stop - with the next SEA Games due in Vietnam in 2021, the gold medallist intends to continue training.

"I train because I love to compete," she said. "I love the intensity and the process of getting there and doing my best when it really counts."

And what would she say to her 12-year-old self?

"I would say believe in yourself. Self-belief is almost everything - mind over matter."