Comment by lpolovets

The article says the tolerance is "3 centimeters in each lane," which feels surprisingly high. The longest race is the men's 1500m freestyle, which is 30 lengths of a 50m pool. That means that in the worst case, pool dimension errors can add 0.9m to someone's race -- about half a second of time in the 1500m. I bet there are races where 0.5 seconds makes a big difference.