For three days, eye doctor Quah Boon Long swam till his arms and legs burned.
He had a target: 1,500 laps.
Yesterday, under the scorching sun, the 54-year-old finally hit his mark.
With that, he won the open category at Safra's Swim for Hope charity drive.
The three-day event ended yesterday and involved more than 2,000 swimmers doing laps at five Safra clubhouses - Yishun, Mount Faber, Jurong, Toa Payoh and Tampines.
Speaker of Parliament Tan Chuan-Jin was guest of honour at the event in Tampines yesterday.
This year, 210,901 laps were swum, raising $155,372 - the most since the event was started in 2011.
The funds raised will be distributed equally to four beneficiaries: Aquatics Heart and Hope, Singapore Disability Sports Council, Rainbow Centre Singapore and Singapore Armed Forces Care Fund.
Adjunct Associate Professor Quah, who practises at the Singapore National Eye Centre, said he was fortunate to be able to combine his passion with charity.
"Swimming is a sport that I have enjoyed since primary school, and back then, I would drag my grandpa to the swimming pool.
"Being in the pool just gives me a sense of peace, relaxation and happiness," he said.
"Over the last three days, knowing that every lap I swam contributed to charity motivated me to push on."
The funds were raised through registration fees, sponsorships, sales of merchandise, general donations, and donations from companies, and were pegged to the number of laps swum too.
Last year, 132,752 laps were swum, raising $106,592.
Participants were mainly operationally ready national servicemen and their family members.
This year's event also featured two new categories to commemorate 50 years of national service: the NS50 individual challenge, where participants had to each clock 250 laps or more; and the NS50 team challenge, where teams of five competed. Both categories attracted 960 participants.
The last category was the Families for Life parent-and-child event, which had 121 parent-child pairs.
It was won by compliance specialist Janice Wong, 42, and her son, Marcus Khoo, 11. Together, the pair swam 506 laps.
"We were just aiming to swim 40 to 50 laps each, so this is a huge accomplishment," said Madam Wong.
"This experience taught us to persevere and it stretched us to reach our maximum potential."