It is understood he quickly disappeared beneath the water's surface and was not spotted again.
Surf Life Saving New Zealand education manager, Allan Mundy, said lifeguards are putting in extra hours just to cope with an increasing number of people in need of rescue.
"We're desperate to get across to people that there have been no drownings between the flags in about 100 years. If people are there, our lifeguards can see them and save them."
Yesterday an 82-year-old English woman in the Bay of Islands became the fourth confirmed drowning of the holidays.
It is thought the elderly woman had been out early with her walking frame and upon arriving home, suffered a medical event that caused her to fall off a bench into a pond, where she drowned.
Water Safety NZ boss Matt Claridge said he is "gutted" by the worst numbers in over a decade.
"The irony is that we launched a campaign with ACC timed intentionally just before the holidays. But there's only so much we can do."
On Christmas Day three people - including a 3-year-old boy - died in a string of water tragedies.
A witness told the Herald on Sunday she was among a group of around a dozen people who had been playing volleyball, when suddenly it was noticed the child was missing.
Around five minutes later he was discovered on the bottom of a lagoon about a metre deep. Attempts to revive the boy were unsuccessful.
Meanwhile, the wait continues in discovering the fate of the missing teenager.
Wanganui mayor Annette Main said the longer the teenager was missing, the less likely the search would end happily.
Main understood beachgoers lost visibility of the boy not long after he was caught in a rip.
She believed he lived locally and many Wanganui residents were helping out in the search.