Miserable Mount Maunganui weather isn't getting in the way of today's Omanu Classic surf lifesaving carnival - though it has forced organisers into a rethink of the program.

Torrential rain and strong onshore winds has hit the upper North Island, meaning the Mount Maunganui New World-sponsored event will be delayed from its lunchtime start.

"We were going to postpone the event until February but the athletes are all really keen to race - they figured they were getting wet anyway - so we're going to meet at the club at 4pm to see what we can get through," says event director Koenraad Groot.

The fast-paced carnival features the Ian Porteous Memorial Ironman, with some of New Zealand's best ironmen set to compete for the prestigious trophy.

Among the favourites are Whangamata Classic ironman winner Andrew Newton, Mount Monster champion Cory Taylor and reigning champion Max Beattie, who is also the current New Zealand ironman titleholder.

Newton (2009) and Taylor (2011) have both won the Ian Porteous race, while two-time winner Damian Munro (1999 and 2008) and Omanu local Ben Cochrane (2012) will also compete.

Beattie (Omanu) admits he'll be looking for redemption, after Midway's Taylor beat him by 5mins in last week's inaugural Mount Monster, while Katie Wilson (Mount) and Danielle McKenzie (Mairangi Bay) look set to continue their women's duel after McKenzie won the 25km women's Monster last week by just 3secs.

It's been 18 years since Omanu clubbie Ian Porteous died, aged just 44, the day before the club's annual long-distance ironman race.

It prompted his good mate Denny Enright to establish a memorial race for the Mount College teacher, conservationist, family man and marathon runner.

AMong other previous winners are Aaron Jarman, Cory Hutchings, Mark Muir and Matt Sutton, who are all past New Zealand representatives.

Jarman (1995 and 1996), Sutton (2006 and 2009) and Munro are the the only double winners.