Doing 1,317 laps in a 50m pool is equivalent to swimming more than 65km - or swimming from Singapore to Batam and back, and then to Batam again.
And 1,317 laps was what Mr Vincent Koh, 40, did over three days from Friday until yesterday, setting a new entry in the Singapore Book Of Records for the most laps swum in consecutive days.
Mr Koh, a culinary trainer, spent about 10 hours in the pool each of those days paddling back and forth.
He was taking part in Safra's Swim for Hope charity drive. Sponsors donated $1 for every lap swum.
The three-day event ended yesterday and involved 1,700 swimmers doing laps at five Safra clubhouses - Yishun, Mount Faber, Jurong, Toa Payoh and Tampines.
A total of $79,038 was raised - the highest amount since Swim for Hope started in 2011. Participants were mainly operationally ready national servicemen (NSmen) and their family members. There were also swimmers from non-profit organisation Special Olympics Singapore and Metta School.
The funds raised will be distributed equally to four beneficiaries: Aquatics Heart and Hope, Community Chest, Singapore Armed Forces (SAF) Care Fund and Singapore Children's Society.
Last year, there were 1,500 swimmers and $76,925 was raised.
Senior Minister of State (Defence and Foreign Affairs) Mohamad Maliki Osman, who is deputy president of Safra, said: "It's an opportunity for the NSmen community to do their bit for charity and it also lets them stay fit."
He added: "We have expanded the programme and we have (swimmers from) the Paralympics and special needs community taking part."
Ms Eileen Ong, 18, a student from Metta School, swam 41 laps in about 21/2 hours.
"It's fun to be swimming alongside so many people and to do my part for charity," she said.
Mr Koh, who works at the Association for Persons with Special Needs, said some of his students were Paralympians and they took part in the event. This motivated him to fulfil his goal.
The father of two, who has been doing distance swimming since 2005, said: "It took a lot of mental preparation, as (having) the willpower is very important. I asked myself - what is my ultimate objective? It was to help others."
To prepare himself, he swam at least three times a week in the past two months, spending three hours in the pool each time.
To clock as many laps as he could over the three days, he took a break once every hour to refuel with energy gels and drinks.
Every two to three hours, he would have some pizza or a burger - what he called "morale boosters".
"Time is of the essence. People say you shouldn't go back into the water after eating, but I've kind of evolved. I can swim well on a full stomach - like a fish. After my last mouthful, I'm right back into the pool," he said.
He also had an MP3 player to keep him going. "It has a mix of fast rhythmic music as well as sentimental pieces, to help me pace myself and not tire out," he said.
And he had the support of his wife Jojo Poon, a 36-year-old teacher, who sat by the pool every stroke of the way.
Said Mr Koh: "My talent is swimming and if I can use it to help others, why not? Hopefully others will see this as an inspiration, too."