O'Connor is a butterfly specialist and the fastest swimmer for his age since club mate and former Olympian Moss Burmester.
At last year's Queensland State champs, he won bronze in the boys' 15 years 200m butterfly in a time of 2:07.04. This was almost three seconds faster than Olympian Kane Radford aged 16, almost identical to Burmester at 17 and is less than two seconds off double Olympic gold medal winner Danyon Loader's national record of 2:05.20 set in 1990.
"I am looking at this development squad as a move in the right direction. I have plenty to work on for this season and next," O'Connor said.
"For this year I am hoping to maybe get some New Zealand records and winning golds at our short course champs in September. The big picture next year, I am looking at the Youth Olympics in Buenos Aries and see how I go with that."
Eiselen made his mark with a standout performance at the 2017 Australian Age Group Championships in April when he won silver medals in the 100 and 200 butterfly.
He swam the fastest he has ever swum, broke the Bay of Plenty records for both events and came very close to the New Zealand records.
"I was stoked with those medals. It was way better than I expected to get, so I was really happy with that, did big PBs and improved heaps," he said.
"It definitely got my FINA points up to make the national development squad. The faster you swim, the more points you get, and the squad is based off FINA points."
Eiselen is a butterfly specialist like O'Connor, with a preference for the 100m and 200m distances. He says O'Connor is the swimmer he wants to emulate.
"I always look up to him, and I try to beat his records that he holds. I like to chase what he did when he was my age," Eiselen said.
Shanahan is a renowned open water swimmer whose stamina is ideal for medium to long freestyle events.
His five medals won at the New Zealand long course age group event clinched his place in the development squad.
"I didn't know if it was going to happen for me this year, but I was definitely targeting it. My swimming has progressed quite a lot over the last two years, and hopefully, it keeps on progressing," he said.
Shanahan is targeting the New Zealand Short Course Champs coming up in September.