The Wanganui teenager had fallen victim to this rule earlier in the 200m breaststroke heats as she made a personal best of 2:55.46 to be fifth fastest qualifier, but missed out because there were two visitors ahead of her.
In her evening 100m final, Schimanski led the race with a 35.46 second time through the first 50m, retaining a steady stroke rate.
However, she was caught in the third 25m section, having to hang on with a final burst to secure second place behind a swimmer from Western Australia.
Schimanski's time of 1:17.38 was a Wanganui Open record and took four seconds of her personal best.
Jacob Smith, 15 secured a finals place in the 200m breaststroke, placing fifth in a Wanganui record of 2:35.36 and also achieved a Wanganui record in the 100m breaststroke in 1:13.93.
Coach Jane Lowe said Smith achieved personal bests in six events including "substantial" improvements in the 400m medley (5:04.79) and 200m butterfly (2:25.83). Sophie Couper, 16, made the final of the 200m backstroke and placed seventh in 2:29.74.
"Elena Forlong, 14 and Laura O'Keeffe, 15 were kept out of finals by the two-visitor ruling," said Lowe.
"However, Forlong set a new Wanganui record in the 200m butterfly with a strong race in 2:34.74.
"Both girls achieved positive personal bests throughout the meet."
The swimmers have a short break over Christmas and New Year before returning to the pool to prepare for regional and national meets over the first four months of 2014.