Confirmation of shallow water effect in swimming pool

Abstract

At the World Swimming Championship Fukuoka 2001, which used a 3 meter depth pool, eight new world records were made in contrast to zero world records at the previous event which used a 2 m depth pool. Why the difference occurred was the motivation for this study. To determine whether “shallow water effect” occurs in a swimming pool, we measured the resistance of a life sized swimmer model in an experimental towing tank with three different water depths of 1.0, 2.0 and 3.5 meters.The results were as follows;1) When compared to 2.0 m depth condition, the resistance of towed model in the 1.0 m depth condition increased by 3.4 % at speed range 2 m/s and above. This can be recognized as “shallow water effect”.2) Also compared to 2.0 m depth condition, the resistance in 3.5 m depth condition increased by 1.1 %. This may be regarded as a measurement error.3) In conclusion, these experiments indicate that there is a “shallow water effect” in a swimming pool at a depth of about 1.0 m in the current competitive swimmers' speed range.