Swimmers will take their first splash towards the Rio Olympics at the State New Zealand Open Water Championships in Taupo this weekend.

At stake is automatic selection to the World Championships later this year, which will provide the platform for a 2016 Olympic campaign.

The championships form part of the two-day State Epic Swim in Lake Taupo, a range of elite and recreational events that have attracted approximately 600 entries for the weekend.

The first two New Zealand swimmers home will earn automatic selection to the world championships in Barcelona, as long as the second swimmer finishes within one minute of the top qualifier in the 10km race on Saturday.

There's also $14,000 of prizemoney up for grabs. The winner of each male and female race will earn $5000, second place $1500 and third $500.

"There is plenty at stake for sure," said Swimming New Zealand open water manager Philip Rush. "We are starting to develop depth in our open water swimming and therefore I am expecting much closer racing this year.

"If swimmers have aspirations for the Rio Olympics then qualifying for the world championships this year is an important stepping stone.

"And no doubt the prize money will provide some additional incentive for all the swimmers."

Queensland-based Cara Bake, former champion and second behind Australia's Melissa Gorman last year, will be the favourite again.

She narrowly missed out on qualifying for the Olympics and will be the key swimmer to beat.

Taranaki's Charlotte Webby, 24, finished third behind Baker last year and was second to her in the State Harbour Crossing recently, although she had led until taking the wrong line around the final marker.

There will be interest in the development of two of the younger swimmers in Grace Sommerville (Ashburton), 16, who was fourth in the open water at the 2012 Junior Pan Pacific Championships and Wellington's Emma Robinson (Capital), 16, who was sixth last year.

Others likely to be prominent are Australian Emily Seymour, fourth last year, former Manawatu swimmer Bridget Maher (Waterhole) and fellow Auckland-based Jessica Marston (West Auckland Aquatics).

Kane Radford, second to Australian Trent Grimsey at Taupo last year, is the clear favourite in the men's race. The Rotorua swimmer has bounced back from the disappointment of missing Olympic selection to win the prestigious Tiburon Mile in San Francisco for the second time. He has returned from a month training with top Australian Rhys Mainstone in Perth.

Former champion Phillip Ryan (Waterhole) is back to full health after battling a shoulder problem last year and is in great shape after winning a 10km open water swim in Ashburton recently.

There's interest in the performance of 20-year-old Nathan Capp, a training partner with Radford and world champion Lauren Boyle at Swimming New Zealand's High Performance Centre, who has been in impressive form.

Others expected to prove strong competition include Troy Balvert, who has returned from completing university studies in Otago to St Peters in the Waikato, national representative Jonathan Pullon, third last year, and talented youngster Isaac Foote (Capital).

The 10km State New Zealand Championship is on Saturday at 10am along with the recreational swims, with the 5km national championships and a masters race on Sunday.

- APNZ