Masterton had 13 swimmers at the championships, which formed part of the two-day State Epic Swim, an event comprising a range of elite and international races which attracted about 600 entries over the weekend.
Aged from 8 years to 40 years-plus, they contested 21 races, some at national championship level and some over the shorter distances from 100m to 2.5km.
Asher Rayner, 15, won the bronze medal in the 13-15yrs girls 10km event in her first swim over that distance and followed up with a seventh over 5km while Sven Tobias, 15, was third in the 13-15yrs boys 10km race and ninth over 5km.
Emma Samuel, 13, was 10th in the 13-15yrs girls 5km championship race and seventh over 2.5km and William Tait, 15, was 12th in the 13-15yrs boys 5km race.
Grace Donaldson, 9, won the girls 9-10yrs 100m swim and was third over 500m, and Oliver Donaldson, 11, was fifth in the 10-13yrs boys 1km race. Maya Champion was seventh and Camryn Watt 12th in the same age group for the girls over 1km while Kayla Watt, 8, was fifth in the 7-8yrs girls 100m race.
Contesting the Epic Swim series for the first time, Ximena Tobias completed the 2.5km and 1km events and Celia Newton and Fiona Samuel the 1km.
A former member of the Masterton club, Isaac Foote, 19, won bronze in the highly competitive open men's 5km championship race and was fifth over 10km.
Kitching said the hot, calm conditions were ideal with the open water competition providing an atmosphere which tied in well with the summer holidays.
Masterton Swimming Club will field a team of 26 at this weekend's Wellington long course championships being held at the Wellington Regional Aquatic Centre.
