KEY POINTS:
Helen Norfolk's switch of focus from medley to freestyle brought a world championship dividend on the final night of the national trials.
The 25-year-old had an operation on her right knee last September and has been troubled by both joints on her breaststroke kick.
She finished ninth in the 400m individual medley at the Athens Olympics but is working on reworking her breaststroke action to get round the dicky knees.
"It has improved dramatically but it's still quite hard to be able to do all the breaststroke training needed for a medley specialist," she said yesterday.
"The plan is to look at my breaststroke in the future and change my technique a bit so the knees aren't used as much and not put under as much strain."
Norfolk won the 400m freestyle at the nationals but was disappointed with her effort at last week's trials.
Now, by winning the 200m freestyle, clocking 2m 0.93s, half a second inside the required time, she can enter the 400m event in Melbourne.
Norfolk, who is one paper away from completing her Bachelor of Arts in psychology at Massey's Albany campus, knows she's not the finished freestyle product, but is happy with progress.
"I have learned a lot," she said.
"It was the first time I went into a meeting concentrating on the freestyle.
"I've still got a lot to learn with race strategies but I was happy with it, it's great to get the qualifying time and it's looking positive for the future."
Whether Norfolk is part of the 4 x 100m medley relay in Melbourne is still to be sorted out.
The programme allows it, but whether her lead-up work enables her to put sufficient time into both the freestyle and medley is yet to be determined.
Norfolk, who is off to her fourth worlds, is excited by the possibilities for the 4 x 200m freestyle, in which New Zealand won the bronze at March's Commonwealth Games and were eighth at the worlds in Montreal last year.
The other star turn on Saturday night was Commonwealth Games gold medallist Moss Burmester, who set his second qualifying time of the day in the 200m butterfly.
He now holds the three fastest times by a New Zealander.
Burmester bettered his morning heat time in clocking 1m 56.89s, 0.25s outside his Games record time set in March.
Head coach Jan Cameron rates it a "very strong team with excellent depth".
"In the main the nucleus comes from the team that did so well at the Commonwealth Games," she said. "They know how to perform under pressure, and can use that experience in Melbourne.
"They got the job done at the world championship trials but also clearly some know there is still improvement to make before March."
New Zealand have qualified in five relays and there are three newcomers who were not at the Games nine months ago - freestylers Michael Jack, Mark Herring and Robert Voss.
However Jack and Voss have contested the Pan Pacific championships in Canada in August.
West Auckland's Lauren Boyle is included despite missing the trials with a bronchial complaint.
In this situation, Swimming New Zealand regulations allow her best time of the year to be considered.
Boyle must pass a fitness test and needs to have returned to training, including a long course 200m freestyle swim, in early February.
TEAM FOR MELBOURNE
New Zealand's world championship team for Melbourne, March 25-April 1:
Individual men: Moss Burmester (North Shore), Dean Kent (North Shore).
Individual women: Liz Coster (North Shore), Zoe Baker (QE2, Christchurch), Helen Norfolk (North Shore), Hannah McLean (North Shore), Annabelle Carey (Aquagym, Christchurch).
Others to qualify for relays and who can enter individual events:
Men: Cameron Gibson (North Shore), Mark Herring (West Auckland Aquatics), Michael Jack (West Auckland Aquatics), Andrew McMillan (Neptune, Dunedin), Glenn Snyders (North Shore), Corney Swanepoel (North Shore), Robert Voss (North Shore).
Women: Alison Fitch (North Shore), Lauren Boyle (West Auckland Aquatics, subject to fitness test), Melissa Ingram (North Shore).
New Zealand have qualified for five relays: Men's 4 x 200m medley; men's 4 x 100m medley; women's 100m and 200m freestyle, and women's 4 x 100m medley.