Joseph Schooling, 19, and Quah Zheng Wen, 18, are both diving into uncharted waters by chasing a record total of gold medals.
Schooling is targetting nine golds while Wen is going after an unheard-of 12 titles, both unprecedented hauls by male swimmers at the region's biggest multi-sports events.
The chances of both scooping the lot are already doomed because they will clash head-to-head in four events in what looms as one of the most eagerly anticipated clashes of the biennial Games.
"I wouldn't have set goals that I didn't think I could achieve," Schooling told Reuters.
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"I think my schedule is hard, but Quah's is even harder, he's in 12!
"But I've got no room or reason to complain. I think I'll get nine, but we'll see."
Schooling, who studies and trains in Texas, has seven gold medals from the last two SEA games but already has sights set on bigger things after starting to make waves on the world stage.
He won a silver medal at last year's Commonwealth Games in Glasgow then became the first Singaporean man in 32 years to win a gold medal in swimming at the Asian Games with victory in South Korea last year.
"I have my personal goals -- I've always wanted to be an Olympic gold medallist as a kid, world record holder and everything," he said.
"So, those dreams are very much still alive. Hopefully I can do that."
Despite their rivalry in the pool, Schooling and Wen are both friends and will join forces in the three men's relays for a Singapore team expected to rule the waves at the city-state's newly-built Aquatic Centre.
Singapore won 17 of the 38 gold medals in swimming at the 2011 SEA Games then 11 of 32 two years ago. With 38 golds on offer again this time, the republic is hoping for a record haul.
Spearheading Singapore's women's team is Tao Li. A former Asian champion Olympic finalist in butterfly, the 25-year-old has already won 24 SEA Games gold medals since she made her debut a decade ago.
At the 2011 Games she won seven golds and is hoping for another big haul on home water.
"We're here to win," Singapore's new head coach, former Spanish Olympian Sergio Lopez, told Reuters.
"I know swimming has been a big sport in the Southeast Asian environment for Singapore bringing in medals."
Singapore's biggest threat in the pool is likely to come from Vietnam, led by teenager Nguyen Thi Anh Vien.
The 18-year-old won three gold medals at the last SEA Games and a year ago, she won the 200 metres individual medley at the Youth Olympics.
(Reporting by Julian Linden)
