Backlash from the waves hitting the side of the pools and then back into the lane makes for an unfair, choppy conditions. Also the most common number of finalists is 8 and there are 10 lane.
8
8 or 6
In Olympic swimming pools there must always be 10 lanes. Although only 8 of these are used it still must have a lane rope between each lane, so there are 9 lane ropes used.
The definition of an Olympic size swimming pool is 10 lanes each 2.5 meters wide, however to prevent the outside lanes being disadvantaged by having to compete with the waves bouncing off the sides of the pool only the middle 8 lanes are ever used.
An Olympic swimming pool usually has 8 lanes, but sometimes has up to 16.
In a competition pool, the lanes are single color for the first and last 5 meters of a pool.
It depends in the standard of the simming race, for Olympic or World Championships then the pool has to have 10 lanes however only the middle 8 are used. For lesser competitions it depends on how many lanes the pool has, usually a minimum of 6 however for smaller and older pools which are very rarely used there may be 4 or 5 lanes
Competitive swimming pools widely vary in width. The width (in feet) changes depending on how many lanes it has. Most competitive pools have either six, eight, or ten lanes. An official Olympic sized swimming pool is 50 meters by 25 meters. It is ten lanes wide.
An olympic sized swimming pool is 50 meter long and 25m wide using 8+2 lanes.
FINA which is the world governing body for international swimming calls for a 50 Meter pool with 8 lanes. However movement is being created for having pools built with 10 lanes, with the outer 2 not being used for competition. (The waves created by swimmers bounces off the side walls and 'slows' down the swimmers in those lanes, thus an buffer is created by not using lanes 1 and 10 in competition). That said, if you are talking about size, Olympic generally refers to the length of the pool, not the number of lanes.
The dimensions of an Olympic pool are required to be 25 meters by 50 meters. PCH=NOT 10
when people swimming lanes divided by lane lines