Sophomore Rebecca Waterson, senior Amalie Fackenthal, right, coach Brian Nabeta, back, and two other DART teammates pose in front of the IUPUI Natatorium scoreboard in Indianapolis at the 2017 NCSAs (Aug. 1-5). In the background, you can see the gap between the waterline and the top of the deck where the wave-cancelling gutters are.

CHLORINE CHRONICLES: Every swim meet is unique; here’s the physics behind it (video included)

Every swim meet is the same. The swimmers warm up, wait for their events, race, warm down and repeat. Nothing changes; it’s the same routine every time. If you have ever thought that, you are in for a surprise.

Every swim meet is unique because of the location, weather, pool type and the nature of the meet that’s being hosted.

What makes swimming in a team-hosted meet in California different from NCSA’s (National Club Swimming Association) in Indianapolis? Ignoring the obvious (such as location), there are actually quite a few important differences.

First off there is water depth. Research has shown that times are faster in deeper water since waves created by the swimmer don’t reflect back from the bottom of the pool and interfere with the swimmer’s forward motion. So why don’t we see Olympic swimming in diving-well-deep water?

In shallow pools I can see the cracks between each tile in the black line. By looking at these lines, I know how fast I’m going. But as the pool gets deeper, I can’t make out little landmarks to see how fast I’m going, so I ultimately feel slower. This psychological aspect, as well as the waves, led scientists to create the perfect Olympian depth of three meters: the same depth as most “fast” pools now.


(Photo used by permission of Waterson)
Sophomore Rebecca Waterson (far left), senior Amalie Fackenthal (far right), coach Brian Nabeta (back) and two other DART teammates in front of the IUPUI Natatorium scoreboard in Indianapolis at the 2017 NCSAs (Aug. 1-5). In the background, you can see the gap between the waterline and the top of the deck, where the wave-canceling gutters are.

Surprisingly, gutter design is also an important aspect of fast pools. The IUPUI (Indiana University – Purdue University Indianapolis) Natatorium, commonly referred to as one of the fastest pools in the world and where NCSA’s was held (which I went to!), has gutters that cancel out waves. The pool I swim in at American River College (ARC) also has wave-canceling gutters, as does the Folsom Aquatic Center (FAC). Wave-cancelling gutters mean that, instead of the edge of the pool being in line with the surface of the water, the wall is two feet above the water line. The wall is open at the water level, however, allowing waves to crash into the opening and be swept away to drains in the four corners of the pool. The gutters are especially helpful to swimmers in lanes one and eight, whose waves would ricochet off the wall in any other pool.


However, temperature is the most important part of a fast or slow pool. At ARC there is a wide range of water temperatures from “so cold our team actually couldn’t practice” to “so hot that it felt like we were slowly roasting.” Because it’s an outdoor pool, the air temperature greatly influences how hot or cold the pool will be, but it isn’t at a constant temperature. At the big meet pools, the water temperature is regulated to stay at a nice, crisp, 77-79 degrees Fahrenheit.

The temperature is important because if swimmers are too hot, they will sweat too much and can possibly overheat. On more than one occasion during a winter meet, I’ll feel like passing out after a race because the pool is so warm. If the pool is too cold, there is a risk that swimmers can’t warm up their muscles enough to race properly.  


(Photo used by permission of Waterson)
The Weyerhauser King County Aquatic Center in Federal Way, Washington, where the annual Husky Invitational is held. Despite not having the same gutters as the IUPUI pool, this aquatic center is known to be extremely fast and was where sophomore Rebecca Waterson got her first Junior National cut in the 100 butterfly.

Like pool depth, lane assignments are another psychological force that can either motivate or scare swimmers. Anyone who’s watched Olympic swimming is familiar with the typical inverted “V” that forms as races grow in length. In a 50 freestyle, almost all the swimmers are shoulder to shoulder, but in a 200 and higher, a distinct pattern forms. This is caused by the fastest person being placed in the middle lane, (usually lane four or five), with the next fastest alternating sides. So if the fastest in the heat is lane four, then the next fastest is lane five, then lane three, then six, two, seven, one and eight is the slowest.


In an ideal world, the lanes should finish in that order, but sometimes the underdogs in lanes one and eight manage to get their hands to the wall first.

In my 100-yard butterfly at Winter Junior Nationals, I was in lane eight (which is closest to the bottom of the screen in the video), and I finished before everyone else.

There isn’t really a physical advantage to being in the inner lanes, just the mental advantage of knowing that that swimmer should be the fastest. As long as the swimmers on the outside believe they can keep up with the lanes next to them and are willing to step up and give it their all, they have a decent shot at winning their heat.

More information on these elements can be found at

By Rebecca Waterson

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