system
Given the following post, respond as if you're commenting on Reddit:
human
[Final Fantasy X] Does the water have anomalous properties or are some people just really, really good at holding their breath? ...Gills?

In the blitzball spheres, in the sea... Everyone seems to just jump in and stay underwater indefinitely, even through intense activity and combat.
gpt
The water contains pyreflys, which work with the machina that make the water float in a sphere. They help support the players while they play, although it also does require training and impressive stamina.