Elderly people, children, and small dogs are most as risk of being knocked over at the beach on Monday as a cyclone threatens to drive huge waves up beaches on Monday, Surf Life Saving warns.
The ex-tropical cyclone is tracking along the East Coast of the North Island and is likely to bring bigger waves and stronger rips from Northland and even as far down as the Wairarapa.
National lifesaving manager Allan Mundy said conditions were expected to get "considerably more dangerous" from Monday, and with school holidays still on, more people were expected to be heading to the beach.
People out walking should stick to dry sand, as surges can go right up the beach, so it's not just swimmers at risk, Mundy said.
"Some of these surges can go well up past the high tide mark and they will knock people over, they can be quite powerful.
"If they're walking, especially if they've got young children, elderly people or small dogs, make sure they stay on the dry sand. If it's wet it'll tell you there's been a wave there before."
Beach-goers should swim at patrolled beaches and if they see a surging wave coming in, head for shallow water and wait it out.
"Be aware that when a large surging wave comes into shore, what was your swimming depth will be lost as the surge carries you out at least an extra metre - that's half the height of an adult."
If they're with children on boogie boards, grab hold of them and make sure they don't get sucked out, he said.
Anyone who does get into difficulty should remember the 3Rs Rip Survival Plan - relax and float, raise your hand, and ride the rip until it stops.
Mundy said many rips will eventually circulate back to shore, so if you feel able, you can swim in once you get closer to shore.
People should not swim alone and should stay within their depth, he said.
Volunteer patrols with flagged areas continue at most beaches around the North East this weekend. During the week some beaches will be patrolled by seasonal Surf Lifeguards.