What Actually Makes a Pool Fast?

Courtesy of  Counsilman-Hunsaker, a SwimSwam partner. 

We all hear this phrase over and over again. “This is a fast pool.” But what does that phrase actually mean? With so many seriously fast meets happening this summer, here are four elements that help define a fast pool:

stock (courtesy of Funky Trunks, Funkita)Water Depth: Water depth might be the biggest factor in making a pool fast. There are two critical considerations when managing water depth of a pool: scientifically producing a fast pool, and psychologically producing a fast pool.

Scientifically speaking, the deeper the water depth, the faster the pool. In a shallow pool, waves will “bounce” or reflect off the bottom of the pool, which causes the entire pool to become more turbulent or “wavy”. Waves do not make for a fast pool, calm water does. The additional water in a deeper pool acts a quelling force to lessen the impact of the wave (or makes it smaller).

So why not have a pool that is 20 feet deep? At some point a deeper pool feels “less fast” than a swallow pool, a concept known as motion parallex. Sprint a lap in a deep diving well and then sprint a lap in a shallow teaching pool. Swimming in a shallow pool, especially one with tile or any pool with many reference points (or marks) on the bottom, a swimmer can feel like they are swimming fast by noting how often or quickly the reference points (tiles) are passing by.

We know most swimming happens at the surface of the pool. Talented swimmers are able to swim some (15 M specifically) underneath the surface of the water performing underwater kicks. While this is happening below the surface of the water, its generally not very deep. Even Michael Phelps doesn’t go much below 6’ off of his start and turn.

Combining all of these items together, scientifically there is also a point of diminishing returns, or a point where a deeper pool is not noticeably faster by a time clock. The Olympic standard of 3 M deep (9.84 feet) is the best balance of both considerations. Water depths near 10 feet gives enough space in the pool to “kill waves” while also allowing a swimmer to “feel fast”.

Duel in the pool stock by MIke Lewis-3654Gutter Design: The design of the pool gutter also plays a big role in quelling or reducing waves. Waves on the perimeter of the pool not only bounce off the bottom, but can also bounce off the sides of the pool. A perimeter overflow gutter can help eliminate any bounce back of a wave on the outside lanes of a pool.

Commonly known as one of the “fastest” pools in the world, the IUPUI Natatorium has a gutter depth of nearly 2 feet. This guarantees that any wave will be absorbed (or killed) by the gutter.

Smaller gutters, especially gutters that can become flooded, will not fully absorb a wave. This can cause the outside lanes to be turbulent. The Olympic standard is to leave the outside lanes empty and only compete in eight of the ten lanes. In high end competition pools in the US, where we typically don’t have the luxury of a full-sized buffer lane, this is provided in an outside buffer lane that is 1-2 feet wide. This also helps a swimmer not feel awkward while they are swimming directly next to the wall.

Temperature:  Like water depth, the temperature of a pool is a balancing act. If the water is the pool is too hot, swimmers will sweat too much and possibly over heat. (Yeah, swimmers sweat when they swim!) Water that is too cold does not allow a swimmer’s muscles to properly warm-up and perform at their highest level. Both of these conditions can cause a swimmer’s muscles to cramp which inhibits their ability to “swim fast”.

Perfect competition water temperature is between 78 and 80 degrees Fahrenheit. Most warm-up pools are 80-82 degrees allowing swimmers to warm-up their muscles without overheating.

(photo: Mike Lewis)

(photo: Mike Lewis)

Lane Width: A common misconception about a competition swimming pool is that there is a standard swimming pool lane width. Swimming lane widths will vary from pool to pool even at high end facilities. Most swimming rule books require a minimum lane width of 7 feet. A typical collegiate swimming pool that is 50 meters long by 25 yards wide, will have a lane width of over 9 feet in the prime competition course. (75 feet divided by 8 equals 9 feet 1 and 13/16th inches plus two 11 and 7/8 inch buffer lanes).

Similar to the water depth, lane width is also a balance between allowing enough space for a swimmer to have room to swim fast and, also, making sure that the swimmer doesn’t have too much room.

In any size lane, it is common for a swimmer to naturally swim towards the edges of the lane, especially a swimmer swimming backstroke. If a swimmer is in a wide lane, it is possible for them to swim longer distances by simply swimming on the outsides of the lane. In a 100 yard race, a swimmer could potentially swim an additional 8 feet (or almost 3 yards) by swimming in a 2 feet wider lane (9 feet versus 7 feet).

The Olympic standard is to have a lane width of 2.5 meters. A true Olympic pool is 50 meters long by 25 meters wide, with 10 lanes. The simply math of 25 meters divided by 10 gives us the 2.5 meters. As previously stated, the two outside lanes are not used in the Olympics so there is no need for an additional buffer, there is a full 2.5 meter buffer!

These four design parameters are just the tip of the iceberg of considerations that play a role in designing a fast pool. Some other considerations that can create another long debate include: lighting, lane rope size, HVAC design, starting block design, spectator seating, deck, water return design, chemical

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About Us – Counsilman-Hunsaker 

Counsilman/Hunsaker Logo - mark only - 300x300The history of Counsilman-Hunsaker is valuable in the context and the confidence it provides. Over the past 45 years, we’ve led the industry by completing more than 1,000 national and international aquatic projects of every size and complexity. In fact, many of the innovations that are now standard in the industry were conceived by our team.

Counsilman-Hunsaker believes that people of all ages are changed for the better through aquatic experiences and that our services reach beyond just solving design, or engineering or facility operational challenges. Our mission is to create aquatic experiences that transform people and communities, which supports our mantra of “Aquatics for Life”. And when we say “Aquatics for Life” we’re talking about the lives of humans we serve through every decision from conception, to the detail of daily operations. By focusing and serving the human experience, our full circle approach to everything we do allows us to be your guide every step of the way from facility audits, to program and design, thru facility creation and day to day operations.

Along the way, we’ve developed an international reputation for innovation and integrity, as people who are passionate about what they do and who do it exceptionally well. Today, our firm consists of an integrated team of designers, engineers and operational specialists with incomparable aquatic industry experience.








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Courtesy of Counsilman/Hunsaker & Associates, a SwimSwam ad partner.

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2 years ago


4 years ago

Hey! Exactly right such as one of the “fastest” pools (Cherrywoods) in the world, the IUPUI Natatorium has a gutter depth of nearly 2 feet.

5 years ago

does climate affect how fast people swim?

5 years ago

does the climate affect how fast people swim?

5 years ago

Don’t forget about air quality!

K. Brown
7 years ago

My daughter’s home pool in high school was Cleveland State. It is a fast pool.

7 years ago

Depth plays huge role and ask a physicist and they will tell you that 12 ft is ideal not 10. Cleveland State was mentioned and it is very calm water due to depth and very deep gutters. There are many outstanding pools in the US and of course UT and IUPUI are outstanding for both swimmers and spectators.

7 years ago

Wide lanes, i.e. Clovis , California LCM…