A Waihī Beach Surf Lifesaving Club representative yesterday said lifeguards were in the water and "giving it their best effort".
Two Coastguard vessels were out searching yesterday, along with the Auckland Westpac Rescue Helicopter, which carried out grid searches in the area, she said.
Police described the sea conditions as rough and two local residents told the Bay of Plenty Times surf conditions were "quite gnarly".
In the past 48 hours, four people have drowned at Langs Beach and Baylys Beach in Northland, and the Police Dive Squad located a body from the Whanganui River yesterday.
A young boy died yesterday after being snatched by a wave as he played in the surf at Napier - the fourth person to die in a horror 48 hours for water emergencies.
Witnesses have described the heroic efforts of two young police officers who risked their lives in a desperate bid to reach the child.
The 9-year-old died at the scene after police received a report of a person struggling in the water off Marine Parade about 3.42pm.
It is understood he was among a group who were swept out to sea from the water's edge.
Water Safety New Zealand chief executive Jonty Mills said the last 48 hours had been a tragic time for families and the country as a whole.
The hot summer was making it inviting for people to get in the water at beaches, rivers and lakes, but he warned water conditions could be unpredictable and changeable.
Mills said there had been 20 water fatalities this year, compared with 22 at the same time last year. The deaths were across a range of ages, activities and environments.
"Any waterway presents a hazard," he said.
With a diverse population and visitors unfamiliar with New Zealand waters, it was important for people to swim between the flags, Mills said.
Police Area Commander Inspector Marty James told Stuff it appeared the Napier group was playing in the surf when the child was swept out.
The sea was rough with large waves crashing on to the beach.
Police were alerted after someone in a nearby camp area called emergency services. Two officers, who were both trained lifesavers, a 27-year-old man and 30-year-old woman, tried to reach the boy.
"They were able to reach him and get hold of him," James said.
"They stayed with him while Coastguard and the rescue helicopter were deployed. The three of them continued to be swept out. Unfortunately the child is deceased."
The helicopter lifted the trio from the water. St John ambulance staff arrived but the child could not be revived.
Napier couple Ani Caird and Clinton Stowers said the two police officers were heroes for going into the massive waves to try to rescue the boy.
"I don't know what anyone was doing going anywhere near the ocean, particularly with children," Caird said.
The couple saw two people, one of whom looked like a surf lifesaver with a waist float, get into the ocean beach just past the breakers before police further down the beach waved at them to get out of the water.
A few minutes later, a helicopter came to the rescue about 1km off shore, dropping a flare about 50m upwind from where the boy and two officers were, heads bobbing in the swirling sea.
Stowers, an engineer who has been in the Air Force, saw the chopper drop a winch to pick up the boy and then the two officers in windy conditions and return to shore. They saw the officers get out of the chopper in their blue shirts and go to an ambulance, but did not see the boy.
"We are both quite distraught," said Stowers after learning the boy had died. "Those two officers did an amazing job and risked their lives. Sadly, it didn't work out in the end," he said.
Emergency services were called to Langs Beach about 11.30am yesterday and three St John vehicles attended and treated one person. Sadly the victim died, police said.
It followed the drowning of a woman on Thursday evening at the notoriously dangerous Baylys Beach, near Dargaville, also in Northland.
The woman got into trouble around 5.45pm, having gone to the aid of her child who was struggling in the water.
The child received only minor injuries.
In Whanganui, a body recovered yesterday is believed to be that of a person who was reported missing while swimming near Somme Parade on Thursday evening.
The Langs Beach, Baylys Beach and Whanganui deaths have been referred to the Coroner.
Surf Life Saving NZ is urging beach goers to be extra vigilant this weekend, and throughout the rest of summer following an increase in serious incidents.
National lifesaving manager Allan Mundy said lifeguards worked hard to keep people safe by patrolling beaches, and operating Search and Rescue squads that were activated after patrols went home.
Nobody was stronger than a rip and swimmers needed to help surf lifeguards help them, he said.
The message was simple: "Swim between the red and yellow flags and remember the 3Rs – relax and float, raise your hand and ride the rip."
- additional reporting Hawke's Bay Today, Bay of Plenty Times