The youngster posted a best time in the 100 metres butterfly to place seventh as well as a sixth in the 200m individual medley.
Despite only sending a small team to the event the club made up for the numbers by smashing many of their personal best times and grabbing several top 10 places.
Johnson said he was delighted with the results from the small squad.
"We have far exceeded our goals for the meet which was to achieve best times and to improve our individual rankings.
"The whole team has showed great character and determination in racing a total of 30 events," Johnson said.
"Last year, we won four points to place 67th nationally. This year we massively increased our team points with a total of 98 points to place 25th overall."
Rotorua youngster David Boles, who was competing at his first national meet, showed excellent pacing and racing skills in the 12-year-old boys' 200m freestyle and 400m freestyle events.
David smashed his best times to post 2:23.12 and 5:00.39 respectively. He also raced a magnificent 400 metres individual medley to place 13th overall, Johnston said.
Fellow squad member Joe Nagera showed both speed and endurance with all his events.
The pick of the bunch came in the 12-year-old boys' 200m butterfly, where he swam under three minutes for the first time to record a 2:57 to take 12th spot.
"Joe was also excellent in the 50m butterfly, 100m butterfly, 200m breaststroke and 100m freestyle.
Joe's 12-year-old twin sister, Ana Nagera, displayed great skill and determination in all her races, Johnson said.
"Ana really attacked her races and was rewarded with an excellent fifth place in the 50m breaststroke with a superb 38.18. She backed up with solid performances in the 100m freestyle, 200m freestyle, 200m medley, 100m breaststroke and 200m breaststroke."
Johnson said all the swimmers from the squad placed in the top 15 in at least one event.
"It was pleasing to witness Bianca break the Bay of Plenty records and to see all our young athletes gain some well-deserved recognition.
"However, this is just the beginning.
"We have high hopes for even more success over the next few years."