"We targeted the meet as one of their goals for the season."
Smith is a breaststroker and will compete in the 50m, 100m and 200m, while Simpson will swim the same distances in backstroke.
Both are also in contention for relay selection.
Smith and Simpson have had extensive training regimes in preparation for the Championships involving eight pool sessions a week as well as gym and dryland sessions, which involve land swim-specific training exercises.
Cooper said the girls are aiming to gain maximum points for the NZ team in their respective events.
"This is the Australian State Teams Age Group National Championships, which means each team has 40 swimmers and they race for team points to decide on the top State Age Group team in Australia," she said. "Swimmers compete in combined age groups of 13-14 years, 15-16 years and 17-18 years. Ciara and Annabell are both 15 years old with Annabell turning 16 on the first day of the Australian meet."
Breaststroker Mia Gordon, 14, was also selected for the team, but is unable to attend.
Smith and Simpson will have little time to recover from the meet as the week after they return they will join the rest of the Northwave team at the 2016 NZ Short Course Championships.
These are at the Owen Glenn Aquatic Centre in Albany.
Cooper said the selection isn't the first accolade for the teenage swimmers.
"Both girls are national medallists, with Ciara winning a silver and bronze medal at NZ Opens and gold medals at National Age Championships and Annabell finalist at Opens in the women's backstroke evens and a medallist at age group level," she said.
The Australian State Teams Age Group National Championships are at the Australian Institute of Sport in Canberra from September 23-25.
