Mr Smith said two-metre high waves were coming in regularly throughout yesterday and were due to reach four metres by 6am.
But the veteran surf lifesaver, who has been working at Papamoa for 16 years and lifeguarding for 35 years, praised the public response. He said he was happy people were heeding calls to swim in designated areas.
"Half of those we've rescued would've drowned if that hadn't been the case," he said. "But with even bigger surf on the way the public are going to have to remain really careful."
Mr Smith said beaches up and down the coast had experienced similar conditions.
He had words of warning, especially for youngsters who ventured out into the surf.
"We're getting a lot of youngsters who are getting into trouble on boogie boards, panicking and getting off to try to swim for safety.
"Stay on the board, someone will come and pick you up. It's when kids get off and try to swim against the current that they get tired and get themselves into trouble."
Mount Surf Club life member Kent Jarmin said they had four rescues yesterday, "which considering the conditions was pretty good as it could have been a lot worse".
Surf conditions at Tay St and the Main Beach intensified from half-metre swells in the morning to 3m-plus by the afternoon.
In some parts of the coast, the sea was reaching the sand dunes.
Mr Jarmin said the conditions were so extreme they had considered closing the beach. Instead they attempted to box people into a flagged area "and did a lot of preventative work".
"It made our job quite tough ... we were continuously bringing people back to the flagged area of the beach."
However, people were positive and very co-operative, Mr Jarmin said.
A young man who had been jumping off the blowhole at Moturiki Island was swept 60m from the rock, out to sea.
Lifeguards in an inflatable rescue boat (IRB) rescued the man after his friend, who suffered grazing after struggling to climb back up the rock, managed to alert them.
A kayaker who set out fishing earlier in the day when the sea was calm was unable to make it back ashore in the heavy swells. The kayaker was brought in by an IRB instead.
Lifeguards were also busy with surfers being swept out, including several with broken leashes.
"It's been a crazy day," Mr Jarmin said.
In the Eastern Bay of Plenty, a father and his 8-year-old son had to be winched to safety when large waves trapped the pair on rocks near the Whakatane Heads.
The pair had walked out on to rocks in the morning but got caught out when the incoming tide's 2.5m waves cut off their path.
In Coromandel about 20 people were rescued yesterday.
A police spokesman says a group of swimmers got into trouble in strong currents off Hahei about 2.15pm, Newstalk ZB reported.
All of those who were swept to sea were rescued.
- additional reporting APNZ
