While the former St Patrick's School pupil was in a field of only five in his age group, the race was more a test of his mental fortitude rather than swimming prowess.
Add to that the fact that event organisers strayed from the scheduled Lake Taupo course to the Acacia Bay North circuit, where the annual Taupo Ironman entrants compete, because of inclement weather.
"I was doing it for the first time and it was pretty cold," says Trent, who entered to gauge his constitution and came away satisfied.
A member of Napier Aquahawk Swim Club, he intends to return next year and possibly raise the bar to the 10km race.
His Aquahawk coach, Frank Wylie, echoes similar sentiments about Trent's character and steely resolve.
"Trent was outstanding and that swim put him in good stead," says Wylie, who took over from coach Mike Lee last February.
Trent clocked a PB of 18m 58.65s at the Hawke's Bay Poverty Bay Championship last Sunday in Gisborne and his coach suspects the Epic Swim contributed to a qualifying time for the New Zealand age-group championship in Wellington from April 18-22.
"Anyone who races 5km in open water ... is a champion by just finishing the race.
"It is like finishing a marathon so winning your age group is a bonus, especially at his young age."
Those who do well in pools tend to emulate that feat in open water, he says, pointing out Kane Radford, 25, of Rotorua, who is the national champion in both 5km and 10km distances.
"Kane spent his teen years doing middle and distance events in pools," he says, emphasising any credits in open water accomplishments should filter back to their pool mentors and parents for initiating it.
Trent, who is a product of Swim New Zealand's Learn to Swim programme, is no exception.
His mother, Karen, is "quite a good swimmer" who at her prime was a triathlete.
In fact, she is Wylie's assistant coach and competed over the same distance in the 50-59 age group category.
"Sometimes mum helps us with what to work on," says the youngster whose sister Alena was fourth in the 12-14 category.
Another sister, Edie, competed in the Mid Epic 1km race, which was part of an overall event that drew numerous Hawke's Bay swimmers.
Mother-and-daughter club members Lisa and Sarah-Kate Birkett, of Havelock, also competed in the 40-49 and 12-14 categories, respectively.
Trent Kamper sees merits in juggling pool and open water pursuits to complement each other.
"It's a lot of fun as there's no limit to how far I can go," he says, enjoying Wylie's input in honing his skills.
Trent has his predilections in the numerous pool disciplines - feeling the butterfly brings the most out in him.
Of course, there's always the desirable distraction of following in mum's footprints in triathlon but it isn't something he can't take in his stride.
"I used to do kids' triathlons before. I haven't been doing it much but when I get better at biking I'll probably do it more often."
