If North Island IRB drivers are expecting a warm welcome at this weekend's BP Surf Rescue New Zealand Championships near Dunedin, they'd best think again.

A cold front is due to hit the deep south just as racing starts at Warrington Beach on Friday afternoon, and the 73 crews at the season-ending event will be tested further thanks to a predicted rising swell.

Sumner crewman Steven Parrat and driver George Thomas competing at last year's BP Surf Rescue New Zealand Championships. Photo: Jamie Troughton/Dscribe Media Services.

That could play right into the hands of the Mainlanders, with Sumner crewman Steven Parrat excited about the weather prospects.

'The cold will hopefully knock the North Island crews around a bit,” says Steven, 'but it will just be another competition for us, as it's the norm for it to be a bit nippy at our carnivals.

Parrat, 25, and his 24-year-old driver George Thomas claimed two of the four premier titles at last year's nationals in Whangamata, capturing the single rescue and assembly rescue crowns, and three of the four premier titles at the South Island championships earlier this month.

Though the Christchuch builders have struggled to get quality time in the boat this season, with the earthquake rebuild in full swing, they should be right in the mix come finals time.

'Winning those two golds last year was great and it let us know that we are competitive with the top crews in New Zealand,” Steven explains. 'But the race can be anyone's in premier grade, depending on who fires on the day, so you can never be over-confident."

Their main competition should come from defending club champions Papamoa, with twins Kirby and Chad Wheeler dominating the North Island championships before Christmas and Liam Smith and Tomee Berthelsen also fast.

Waimarama's Mike Harman and Ben Cross have won plenty of national titles in the past, while Brighton pair Simon Roberts and James Walters have even more local knowledge than the Sumner duo.

The women's division is even more open, with 19 crews - including nine from South Island clubs - battling it out.

St Clair have unearthed another star female duo following the retirement of the world champion Laughton sisters, with Briar Taylor and Maysha Aherns clean-sweeping the South Island titles and helping the Dunedin club take overall honors ahead of arch-rivals St Kilda.

Fitzroy's Katie Watts and former New Zealand iron-woman champion Jamie-Lee Reynolds collected two golds at the North Island champs, while East End, Opunake, Waimarama, Sunset Beach and St Kilda also have strong crews.

Racing starts at 1.30pm tomorrow and finishes on Sunday afternoon.

BP Surf Rescue New Zealand Championships:

(Warrington Beach, Dunedin)

Friday (1.30pm start): Tube rescue heats and finals

Saturday (9.30am start): Assembly rescue heats and finals, mass rescue heats

Sunday (9.30am start): Mass rescue finals, single rescue heats and finals, teams race heats and final.