Aquatics Blog


Competitive swimmers execute headfirst dive entries from starting blocks into pools where water depths can vary. If the swimmer’s head strikes the bottom of a pool, this could result in damage to the cervical vertebrae, thus may result in quadriplegia. This was a significant topic of conversation in the industry in the early 1980s when a varsity swimmer at a university was injured in practice.

In prevention of Cervical Spinal Injuries (CSI), a cohesive plan currently does not exist in a minimum uniform water depth, which would lessen the likelihood of catastrophic tragedies. “No Diving” signs are posted when the water is less than five feet deep in some states, and four feet in others. This is still more inconsistency. What is the right depth for balancing safety and function for in a swimming pool? What depth? And what about recreation/therpy swimmers?  

Here’s the Confusion

Up until the early 2000s the industry standard water depths were in the 3 feet 6 inches to 4 feet range. November 2001, the NFSHS changed minimum water depths from 3 feet 6 inches to 4 feet. USA Swimming followed suit with a note that teaching off a starting block shall be limited to 5 feet water depth. 

Policy makers, swimming pool rulebooks, and state swimming pool codes still lack research in regard to water depth requirements under starting blocks. Moreover, water depth requirements under starting blocks in governing bodies’ rulebooks not only conflict with one another but often conflict with state statutes, which may in turn conflict with local county and municipal ordinances.  

The following shows a variance among the four aquatic governing bodies, as well as the YMCA and the American Red Cross, in regard to water depth for headfirst entries. 

Federation Internationale DE Natation (FINA): 4 feet 5 inches.

National Collegiate Athletic Association (NCAA): 4 feet.

National Federation of State High School Associations (NFSHS): 4 feet.

USA Swimming and US Masters Swimming: 4 feet for racing, 6 feet for teaching.

YMCA: 5 feet.

American Red Cross: 9 feet.  

The Research

There has been plenty of research on the health advantages of recreation, lesson, fitness, and competitive swimming and how it impacts safety and lifestyle. Here’s a nice shout out to water safety programs and ongoing swim lessons nationwide. Even though more and more people are exposed to a growing number of swimming pools at new aquatic facilities across the nation, drowning death rates in the United States have declined in the last decade according to the Centers for Disease Control and Prevention.  

Should We Build All-Deep Water Pools?

Is the answer that we build all-deep water pools? And if so, how deep? Twenty years ago swimmers swam nearly their entire race at the surface. Today most elite swimmers swim a large percentage of their races 3 to 4 feet below the surface, utilizing a butterfly (dolphin) kicking technique. In a shallow pool, swimmers utilizing this technique may face higher drag forces and may even have to modify their technique.  

Because of these factors, pool depth more closely correlates to swimming speed today than in the past. Championship pool depth may impede many instructional, fitness, and recreational opportunities and consequently, revenue potential. And since people frequent pools for a variety of reasons—fitness, relaxation, instruction, competition, and therapy—today’s swimming facilities do not just accommodate competitive swimmers but are multidimensional centers encompassing all types of swimmers.  

To provide a fiscally sustainable facility, multiple users must be able to use the same space for different purposes at different times. Building an all deep-water competitive/lesson pool with a moveable floor for altering water depth for various purposes can be provided; however, the cost of such a floor system is often considered prohibitive. The following shows preferred water depths for various types of swimmers.

0 – 3.5 Feet



        Wellness / Therapy 

3.5 – 5 Feet


        Lap Swimming

        Wellness / Therapy 

6 – 10 Feet

        Competitive Swimming

        Water Polo

        Synchronized Swimming 

11.5 Feet +


In addition to variances of water depth for different types of swimmers, pool water temperature is another consideration in multi-use pools. Water too cold causes muscles to tighten while water too warm causes overheating and lethargy. Water temperature at 79-81° F is ideal for competition while the natatorium is maintained at two degrees above the pool water temperature to minimize evaporation. The following shows different water temps (in natatoriums) for various types of swimmers. 

Competition Pool                    =          82 ° F, competition and training prefer 78° to 82°

            Air Temperature          =          84° F (or 2° above water temperature)

 Leisure Pool                            =          82° to 86° F

             Air Temperature          =          84° to 87° F (if in separate space)

Diving Pool                              =          84° to 86°

            Air Temperature          =          86° to 87° F (if in separate space)

Therapy Pool                           =          88° to 92° F

            Air Temperature          =          86° to 90° F (if in separate space)


If you build an all-deep water pool with a movable floor, you still have a problem with water temperatures. Competitive swimmers like it cooler than recreation swimmers who like it cooler than warm-water wellness seekers. Building multi-faceted facilities with separate pools for various types of swimmers seems to be an answer in providing various water depths and proper water temperatures at aquatic centers. Swim meets, lap swimming, deep-water aerobics, life saving instruction, diving lessons, survival swimming, synchronized swimming, water polo, deep-water aqua jogging, underwater hockey, and scuba instruction can take place in an all deep-water competitive/lesson pool, which frees up the warm-water therapy pool for water wellness seekers, and the leisure/recreation pool for swimmers who want to use the play features such as waterslides, current channels, participatory play structures, etc.

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