Neptune's Erika Fairweather and Caitlin Deans will battle former Dunedin swimmer Carina Doyle at the open championships in Auckland.
Entries for the meeting were released this week, and the trio will enter among the favourites in the 200m, 400m and 800m freestyle.
Neptune's Fairweather was the star at April's national age group championships, shattering the national 15-years records in each event.
She managed silver in the 200m and 400m at last year's open championships, trailing Doyle in each.
Doyle, who now competes for North Shore but is from Dunedin, will have a tougher challenge this year to defend her titles.
In the 200m both enter with identical seed times of 2min 00.01sec.
Meanwhile Deans had a stellar short course national championships late last year.
She too claimed a national record and went on to represent New Zealand at the short course world championships in China.
Neptune's Jessica Scott will look to make a major splash in the butterfly races, while also competing in the 50m freestyle and 200m individual medley (IM).
Ben Carr will represent the men in the backstroke and butterfly over 50m and 100m.
Kiwi's Madison Wills will contest the 50m, 100m and 200m breaststroke, as well as the 200m and 400m IM.
Wanaka Paralympian Hamish McLean is one of 24 para-swimmers in action, competing in freestyle and IM races.
Zenith's Katie Short will also compete in the para events in both freestyle and backstroke.
