New Zealand's best open water swimming specialists have won this year's State Harbour Crossing.

Rotorua's Kane Radford claimed the mens race, but didn't have it all his own way, with pool specialist and London Olympian Dylan Dunlop-Barrett pushing him for the entire 2.9km journey across the Waitemata Harbour from Bayswater to the Viaduct Harbour.

Kane RadfordKane Radford
(Photo: State NZ Ocean Swim Series; click to enlarge)

The race, held in calm and flat conditions, was a tight throughout with Australians Jarrod Poort and Wally Eggleton also in the mix, along with Auckland's Nathan Capp and Phillip Ryan.

Radford and Dunlop-Barrett, in fact, tangled several times during the race, as each tried to get the ascendancy.

But in the end, Radford got his nose in front right at the end, to claim the race by three seconds, with Poort third, another two seconds back.

"Those boys really pushed me hard out there, so I give them credit, as it's something they don't normally do," he said.

Radford's now won this race five times from six attempts, and has ensured he's sent a strong message to his rivals, like Poort, and another Australian Rhys Mainstone, who'll be featuring in series in the New Year.

"It's not an easy series this one. You can't just rock on up and win it," he said.

The womens race was far more clearcut with Taranaki's Charlotte Webby comfortably winning.

Webby was expecting a tough race with Wellington's Emma Robinson, a World Championship representative for New Zealand earlier this year, and talented Australian Jessica Walker.

But Webby made the race her own clearing away to win by 32 seconds.

"This is a huge confidence booster. To get a win is amazing. I know with sport it can be anyone's day on a given day, and today was my day.

In all, almost 1700 swam in the Harbour Crossing today including several well-known names, with one being former All Blacks winger and now Blues rugby coach Sir John Kirwan.

He swam the race with former New Zealand triathlete Rick Wells, who helped Kirwan with his training regime.

The pair finished in 51:06.

"I'm really happy. It was a fantastic experience. It was great swimming with Rick and I got into rhythm and enjoyed it.

"I'm a proud Aucklander. So, to be actually able to swim the Harbour that you've been driving around and looking at your whole life, is a real achievement," Kirwan said.

Results: 2013 State Harbour Crossing

Men

1. Kane Radford (Rotorua) 33:59
2. Dylan Dunlop-Barrett (Auckland) 34:02 +0:03
3. Jarrod Poort (Warilla, NSW) 34:04 +0:05
4. Nathan Capp (Auckland) 34:07 +0:08
5. Wally Eggleton (Queensland) 34:30 +0:31
6. Phillip Ryan (Auckland) 34:38 +0:39
7. Troy Balvert (Cambridge) 36:17 +2:18
8. Kaiori McGuinniety (Nelson) 36:17 +2:18

Women

1. Charlotte Webby (New Plymouth) 36:54
2. Jessica Walker (Gold Coast, Qland) 37:26 +0:32
3. Courtney Carson (Lower Hutt) 38:28 +1:34
4. Emma Robinson (Wellington) 38:40 +1:46
5. Grace Sommerville (Ashburton) 38:41 +1:47
6. Paige Schendelaar-Kemp (Auckland) 38:44 +1:50
7. Kirsty Wannan (Auckland) 40:03 +3:09
8. Liana Smith (Waiuku) 40:37 +3:43