SAMANTHA Yom has perfect vision but is squinting under the scorching sunlight, her eyes barely open as she lifts the protective covers off her boat at the National Sailing Centre.
In the next 30 minutes, she must transform from schoolgirl in pinafore to suited-up sailor and convert her dinghy from sleeping sailboat to rigged-up raft.
A teenager giggling with team-mates on land will soon become a competitor on water.
The bus that ferried her from campus to training earlier had arrived late, so the 15-year-old Raffles Girls' School student is now behind time. But she remains a collected figure.
After a decade of plies in ballet and symphonies on the piano, poise has become innate. Her nimble fingers, as adept at tying stopper knots as they are at playing the cello, have the benefit of muscle memory.
But coach Tracey Tan announces the day's training will focus on starts, and at once this 2014 Nanjing Youth Olympic Games (YOG) gold medallist breaks into a sheepish laugh.
Jostling with opponents for the best position, you see, is not Samantha's strongest suit.
"It's my weakness," the Year 4 student admits. "You need to be aggressive in starts. I'm competitive, but not aggressive.
"I tend to choose to give way rather than fight with people - and that's not what you're supposed to be doing in starts."
That afternoon, even without the stifling atmosphere of competition, Samantha's preference for the conservative showed.
Through the first three starts, she stuck to the safer option - until Tan mandated that she attempt a "port tacker", starting by sitting on the boat's left, its port side.
Much tougher, much riskier, but also much more advantageous if executed well.
Samantha made history when she won the YOG women's Byte CII event last year. Together with Bernie Chin's win in the men's category, it was the first time Singapore had triumphed at a Youth Olympic event.
That triumph has earned her a nomination for The Straits Times' Athlete of the Year award.
But just months before the Games, then-coach Fernando Alegre was so concerned that she would cower at the sight of a fight that he sent this ballerina for muay thai classes.
"So that I could learn controlled aggression," she recalled of her two-month foray into the Thai combat sport.
Perhaps it was precisely a timely summoning of that boldness that triggered a comeback at the Jinniu Lake in China, leapfrogging table leader Odile van Aanholt of the Netherlands in the final race.
"That race keeps repeating in my mind. I still look back in disbelief. You know that saying, 'It always seems impossible until it's done'? I believe that more now," said Samantha, referring to the late Nelson Mandela's famous quote.
If that win has made her more confident, it has also brought her more pressure.
She said: "You can't keep harping on that one achievement. I've done something I never thought would be possible - that means I should be able to do even better in the future."
So, six days a week, Samantha toils at her craft, doing what sometimes feels mundane and is always exhausting.
Today, for two hours, she counts down the seconds before each start under her breath. An imaginary line cuts through the water between two buoys in front of her, and she times her advance as her coach judges close by.
Tan blows the starting whistle.
"Four seconds slow!"
"Poor form, my friend!"
Samantha is not comfortable, but she recognises this is her chance to "try something new", to "master what you already know".
She finally gets back to shore, but training is not yet over. The boat needs to be hosed down, de-rigged, and she still needs to hit the gym.
It is a lonely and fearful sport, for it is just Samantha, a speedy yet unstable boat and giant tankers out there in the waters. There have been painful bruises and uncertain days spent questioning why she still keeps at it.
But for her, the hardest thing about pursuing sport - not just sailing - remains the risks.
Attempting manoeuvres she is not used to. Staying in the sport despite struggling. Sacrificing her beloved dance studio for the sea.
Said Samantha: "If I want to achieve a goal, I will put in all the work needed to achieve it."
Even if it means squinting and not having perfect vision of what lies ahead.