On July 20, 2012, the Facility Design and Construction Model for the Model Aquatic Health Code (MAHC) was posted for public comment due October 14, 2012. In section 4.8.3.3. a single sentence could change the industry standard for minimum depths under starting blocks to 6 feet and 7 inches for a distance of 20 feet. This could have a significant impact on swimming pools around the country and industry professionals are encouraged to participate in the public input process. In order to make an informed decision, the following data is offered for consideration. 
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. Before 1970 this was unheard of, but in the early 70s, goggles were introduced and different methods of completing racing dives were developed to maximize speed and minimize the potential for losing goggles.
In prevention of Cervical Spinal Injuries (CSI), a cohesive plan currently does not exist for 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. There is still more inconsistency. What is the right depth for balancing safety and function for underneath starting blocks? Moreover, should we build all-deep water pools? What depth? And what about recreation 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 National Federation of State High School Associations (NFHS) 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 6 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
The Counsilman Center for The Science of Swimming completed a study in 2011 on racing start safety published in the International Journal of Aquatic Research and Education. Joel Stager, Director reports the water depth needed to prevent contact with the bottom of the pool that could result in injury is well beyond 6 feet 7 inches and the critical link to safe starting block starts is education. In summary this research indicates:
- Swimmers go deeper in deeper water
- Older swimmers go deeper than younger swimmers
- All ages ( and experience levels) of swimmers go shallower when asked to do so
- There are differences in head depth as a function of block height
- Virtually all starts are fast enough to cause injury if an impact should occur
- Very few swimmers go deeper than five feet even in seven feet of water.
We are at a crossroads between safety versus programming when they should be compatible. The key to safety in this matter is instruction and how participates learn how to dive. The reality is no water depth is safe without proper instruction. When making an informed decision, one must balance the threats and benefits from an activity. 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.
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 pool would significantly limit other uses such as recreation, lesson, fitness and therapy. The following shows preferred water depths for various types of swimmers.
0 – 3.5 Feet
– Toddlers
– Recreation
– Wellness / Therapy
3.5 – 5 Feet
– Recreation
– Lap Swimming
– Wellness / Therapy
5 – 10 Feet
– Competitive Swimming
– Water Polo
– Synchronized Swimming
11.5 Feet +
– Diving
Unintended Consequences
Some may suggest that the Facility Design and Construction Module is limited to new construction and would not apply to existing facilities. I would suggest that given the United States legal system this is naive. I cannot envision an outcome that defines separate solutions water depth solutions for new and older pools. In 2001 when the NFSH changed the minimum depth standard from 3 feet six inches to 4 feet, many high school pools moved the starting blocks from the shallow end of the pool to the deep end. For pools without diving wells, this proposed change would likely require structural modifications to the pool shell. To renovate a six lane 25 yard pool from a maximum water depth of 4 feet to 6 feet 7 inches for a distance of 20 feet in front of the pool edge is estimated to be in the $200,000 range. Not only will the pool depth be effected but the mechanical equipment will need to be upgraded to services the increased water volume. For new construction the differential cost is not as great with an estimated increased cost in the $20,000 range.
Conclusion
The State of Michigan is the only state that requires water depths under starting blocks to be 6 feet 7 inches. If the MAHC codifies this unique standard it will change the national standard as defined by the governing bodies of sport. In this writer’s opinion, the unintended consequences maybe the dramatic decline of competitive swimming activities in the United States similar to the effects of removing high dives across the country in the 1980’s and 1990’s. If this happens what are the negative health effects on childhood obesity and an increased sedentary lifestyle?