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. While it may seem like it's to replenish liquid that sloshed over the sides after a dive, 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, 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.” 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. While it seems like Olympic divers are probably skilled enough to avoid this anyway, it has happened before.