system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do they use a hose to splash water during high dive competitions?
gpt
It makes the surface of the water visible, so the diver can see where it is as they are aligning to go through it.  If the water was still, it would be very hard to see where it started.  As others have said, it also ripples the surface, giving a little smoother transition from air to water and air to water.