The annual State New Zealand Ocean Swim Series is back and bigger than ever before, with confirmation that it's now one of the top three richest open swim series in the world.

$20,000 is up for grabs for both the leading man and woman, and just the FINA Open Water Swimming Grand Prix and the FINA 10km Marathon Swimming World Cup rank higher than New Zealand's series.

State New Zealand Ocean Swim Series event director Scott Rice says the event has already attracted a number of top class swimmers, including 2012 Australian Olympians Ky Hurst and Melissa Gorman and the fastest man ever to swim the English Channel, Trent Grimsey.

New Zealand's best Kane Radford and Cara Baker are also confirmed starters.

The series has six races, with the first the State Paihia Classic, a 3.3km swim from Russell to Paihia, on Saturday week (November 10th). Two of the other races are held in Auckland (including the State Harbour Crossing), while Wellington, Akaroa, and Mount Maunganui host a race.

To be eligible for the prize money, each swimmer must compete in three of the six events. The winner of each race will receive 100 points, with the remaining competitors awarded points as a percentage of the winner's time.

The series will conclude with double points on offer for the final event, the State King of the Bays, on the North Shore in April 6th next year.

Event director Scott Rice: "We wanted to ensure a dramatic conclusion to the series, and this was the best way to do it. The quality of swimmers competing in New Zealand over the summer will be outstanding."

For more information see www.oceanswim.co.nz/event-info/elite-series.