I think that the depth of a pool may affect a swimmer’s speed by a small amount. In a shallow pool, when a swimmer pushes the water down during their stroke, the water may hit the bottom of the pool and then bounce back, creating turbulence and slowing them down. This would be similar to how swimmers swim faster in the middle lanes than the outer lanes due to the water going outwards and hitting the wall, creating turbulence. This is similar to a beach, where the waves get stronger as they approach the shore. That’s because the roots of the waves bounce off the sand as the water depth gets shallower, creating stronger waves. Although in a pool, I think that the water depth will only make a small, but measurable difference in a swimmer’s speed.

In the 2024 summer Paris Olympics the pool used for swimming was only 2.2 m deep, which was about 80 centimeters shallower than the pool used for the Tokyo Olympics in 2020. The standard for competition pools used for events like the World Championships, Pan American Games, and the Olympics is 3.0 m.  Keating (2024) explained that the depth of a pool also has an impact on the waves at the surface on the water. In a shallower pool, the waves are slower, so they stay longer therefor slowing the swimmer down. We also found that another variable that may affect a swimmer’s speed is the salinity of the water. Killarney is known for having more salt than the average pool. A pool with more salt would make a swimmer more buoyant, therefore making then swim faster.

Keating S. 2024. Is the shallow pool in Paris really slowing Olympic swimmers down? Here's what the science says. Phys.org, August 1 2024

A few variables that may have afected my project are:

The tempature of the water in each pool

The salinity of the water in each pool

The time of day the swimmers swam at each pool

The time between when the swimmers swam, and the last time they had swam

The approach was to time swimmers in a deep and shallow pool. First, I asked my coach Tammy for permission to time a few swimmers during practice. We had six swimmers from my team swim six 50 metre (m) freestyle laps at each of the two pools where we train: MNP Community and Sport Centre and Killarney Aquatic and Recreation Centre. The pool at MNP has a consistent depth of 1.8 m, and the pool at Killarney slopes from 1.1m to 1.4 m with an average of 1.25 m, making MNP 0.55 m deeper. We had the swimmers swim in lane one at both pools so that the turbulence from their lane would be the same and not influence the results. The swimmers swam on a 1:30 interval at threshold effort. Each time the swimmer finished one of their laps, my coach and I took their time on a stopwatch, and I wrote it down on a data table. Then I calculated the average for each swimmer at each pool. I made sure to control all the variables, but couldn’t control the temperature of the water. At MNP I used an infrared thermometer to measure a water temperature of 27.1 degrees celsius. At Killarney the temperature of the pool was 28 degrees celsius.

In conclusion, there was no consistent difference in the swimmers times between the two pools. It’s possible that the depth of a pool only has a very small difference that I was not able to measure. Also, I think that there were a few variables that may have had a bigger effect than I thought. A few variables could have been the temperature of the water, the salinity of the water, and also the time of day and the amount of rest. At MNP, the swimmers swam at 6:00 AM, at Killarney however, they swam at 6:00 PM, which gave them a whole school day before they swam. Also, before the swimmers swam at MNP they only had 12 hours in between then and their last workout, when they swam at Killarney, they had had 58 hours since their last workout. With a larger group of swimmers doing the experiment and less variables it may have been possible to get a more consistent difference.

The main source of error in the measurements of the swimmers' times was variation in the time it took me to press the button on the stopwatch. But that variation likely was less than one second in each swimmer's times. More significant were the variables that may have influenced their swimming times. Since I wasn't able to control these variables, they can be thought of as sources of error in the experiment. These variables consisted of:   

The tempature of the water in each pool

The salinity of the water in each pool

The time of day the swimmers swam at each pool

The time between when the swimmers swam, and the last time they had swam

Keating S. 2024. Is the shallow pool in Paris really slowing Olympic swimmers down? Here's what the science says. Phys.org, August 1 2024

I’m thankful for my coach Tammy Anderson, my teammates who volunteered for the project, and my dad who reviewed my work.