I was surprised to discover that the starting blocks at each end of the pool at summer Long Course Nationals were set at different heights. The height of the blocks closest to the indoor pool was 29.5 inches—3.5 inches higher than those on the far end.

I was curious to see how much effect this would have on a 50-meter event. I dug out my old physics book and made some calculations. I assumed two six-foot tall swimmers swimming 50 meters in about 24.9 seconds. I assumed that both swimmers could dive about 10.25 feet—yielding a hang time of about 0.6 seconds. Given those assumptions, the swimmer on the lower block would have to swim an extra distance of 3.4 inches. This would take about 0.03 extra seconds.

The results do not change much for shorter or slower swimmers. Two 5-foot tall swimmers diving 8 feet and swimming at a speed of 5 feet per second would also have a 0.03-second difference.