Surface turbulence
It is about the choice of the corridors. Modern corridors also reduce to a minimum the disturbances received by each swimmer, striving to shower them as much as possible.
The more inefficient the corridors are, the more the waves will interfere.
The width of the corridor
It must be balanced so that the competitor has neither too much space nor too little. Imagine that you are swimming in a rather wide and spacious corridor. It very often happens that the contestants find themselves right next to the corridor. Then again in the middle and in general to move along its entire width. It may sound unrealistic, but there is a chance that it happened that the event was 100 meters, but in fact we swam 102 meters. That alone speaks for itself as to what will happen to the achievement.

The Olympic standard is for the width of the corridor to be 2.5 meters, i.e. the entire width of the pool is 25 meters.