As a former swimmer, this anime truly shows the fun in swimming. I'm specialized in Forward-Crawl (freestyle) too which makes me can relate to Nanase a lot.
I have never experienced relay but watching how fun they're having and the friendly competitiveness makes me want to go back to the pool.
To me, it captures swimming perfectly. Especially in the relay ones.
Good job, KyoAni for visualizing it well!