Bay of Island's Emilia Finer (13) qualified to swim at all events in her age group at the competition and has chosen to take on all eight.
She is ranked inside the top 10 for 100m and 200m butterfly, 400m and 800m freestyle, and the 200m individual medley.
Teammate Kori Brown (14) is ranked in the top 10 for 100m and 200m breaststroke.
Tyler Jepsen, also 13, has seven swims and is ranked in the top 10 for three events, including third place in 400m freestyle.
Madeline Whittam (14) is ranked second in 50m and 100m breaststroke, and in the top 10 for 200m breaststroke.
Annabell Simpson (17) is ranked in the top 10 for her three backstroke events, second in 200m back.
Bream Bay's Paul Linton (17) is ranked in the top 10 in the 16-18-year age group for 50m back.
Other Northland swimmers competing are Archie White (Bay of Islands), Rose Linton, Luca Matenga, Rebecca Reade, Jackson Somner-Allen, Abby Wright (all Bream Bay), Nellie Clark, Nathalie Hull, Quin Walden (Northwave), Grace Hilton-Jones and Cameron Ludgate (Whangarei).