Why Do They Spray Water in the Olympic Diving Pool Between Dives?

If you’ve tuned in to any Olympic diving events, you may have noticed that sprinklers spray water over the surface of the pool between dives. It seems like it could be to replenish liquid that sloshed over the sides after a dive—but world-class divers hardly make a splash.

So what’s the point of wetting something that’s already as wet as it could possibly be? In this case, as Sporting News reports, it’s a safety measure. The Fédération Internationale De Natation (FINA), which oversees Olympic swimming events, mandates “surface agitation … to aid the divers in their visual perception of the surface of the water” [PDF].

In other words, the sprinklers create ripples across the water, which makes it easier for divers to see how far they are from the surface of the pool. That way, they can time their flips and twists to culminate right before they hit the water, avoiding a botched landing or full-on belly flop. And while it seems like Olympic divers are probably skilled enough to avoid this anyway, as you can see below, it has happened before.

The sprinkler system isn’t the only acceptable method of agitating the surface. In fact, FINA actually lists an “underwater bubble machine” before mentioning sprinklers. “The machine shall only be used for the purpose if it creates sufficient water agitation when working with a very low pressure,” the rule book explains. If not, officials should use above-ground sprinklers.

Specific, yes, but that’s sort of the theme of the rule book. Diving pools must also be at least 78.8°F (26°C), and if they’re outdoors, “springboards and platforms are recommended to face north in the Northern Hemisphere and south in the Southern Hemisphere.”