A new water safety system that uses sonar technology to help lifeguards spot swimmers in trouble is drawing the praises of park managers and water safety experts. Park insurers say the system can mean discounts in premiums, and at least one insurance company is urging its clients to install the system.

The system, called Sonargard, alerts lifeguards to swimmers in trouble by using sonar devices placed along the bottoms of swimming pools. Sonargard notifies lifeguards if a swimmer sinks to the pool bottom.

Increased Safety - Lower Premiums!

At The Beach, a park near Cincinnati, General Manager Walt Davis is installing the system in his park's main pool. Like most of his peers, Davis' worries about safety rise each season with the temperatures and size of the crowds. More than 5,000 swimmers are likely to cram the park on a typical summer day. By late afternoon, when pool water becomes cloudy and the sinking sun reduces visibility, lifeguards have to work all the harder to spot struggling swimmers.

Davis said he signed on to the Sonargard system because he is convinced it will be an extra boost in safety at the park. "I think it's a revolutionary concept," said Davis. "If it works, I can go home and sleep at night."

The Beach's insurance company provided an added incentive to install the Sonargard system — a big discount on the water park's insurance premium. That savings, Davis said, will pay for his $44,500 Sonargard system in two years.

The Columbia Swim Center in Columbia, Maryland helped to pioneer sonar technology's acceptance and installed the first, full-fledged Sonargard system in their 25 meter pool.

Sonargard, which arrived or the market late last year, is the latest brainchild of Gary Zuercher. In 1972 Zuercher introduced the idea of swimming pools with waves to the U.S. through his company, WaveTek. For 10 years WaveTek was the only wave pool company in the country, installing over 150 wave pools stateside, in South America and in Asia. Zuercher sold WaveTek in 1984. By early 1988 he approached Tom Lynch, a noted sonar scientist, with a new idea — using sonar technology to help lifeguards do their job.

Lynch "reacted with skepticism at first," said Zuercher. The two developed and tested the idea through the next year — first in a laboratory fish tank, later in a swim club in Cleveland, and finally by installing a full-fledged system in the municipally-owned Columbia Swim Center in Columbia, Maryland The swim center is near the Arlington, Virginia office of Zuercher's company, Sonar International, Inc.

According to Zuercher, the 25-meter indoor pool at Columbia turned out to be "the toughest pool in the United States" in which to initiate the sonar system because of two large water slides that emptied into the pool. Water from the slides created whirlpools that formed ghost images picked up by the system. After adapting the system to accommodate the presence of the slides, Zuercher real-

ized the system could be adapted to almost any pool design.

Zuercher reports the Sonargard system has worked flawlessly when tested in a wave pool in Chicago. His company currently is installing in Wet'N Wild's wave pool in Orlando, Florida.

How Does the Sonargard System Work?

A string of sonar "transducers" — disks that measure about four inches across — is mounted along the sides of a swimming pool's deep end. Each disk monitors a six-foot wide corridor on the floor of the pool. Every swimmer and diver is detected when passing through a corridor; the system alerts lifeguards only if a person remains relatively motionless on the floor of the pool for at least four seconds. In such a case an alarm sounds and a light on the panel at the lifeguard's station shows the exact corridor where the distressed swimmer can be found.

Statistics reflect the potential value of a rapid alert system — the quicker the lifeguard notices a swimmer in trouble, the better the chance of survival. According to a Harvard University study, swimmers submerged for one minute have a 98 percent chance of survival; when submerged three minutes, the survival rate drops to 72 percent; if submerged for five minutes, a swimmer has only a 25 percent chance of surviving.

Those who survive nearly drowning often suffer permanent brain damage. The degree of severity depends on how long the victim was under water. According to a 1988 report by the National Safety Council, more than 94,000 people are injured in swimming accidents each year. In 1987, 5,300 drownings occurred, making drowning the third leading cause of all accidental deaths in the U.S.

A display unit monitors the pool and senses the location of any distressed swimmers. The photo shows an enlarged view of the Sonargard display unit and its location at the lifeguard's station. (Arrow indicates position.)

Jeff Ellis is a Houston-based water safety expert who trains lifeguards and audits water parks and pools to check their safety standards. Ellis has worked as a consultant to Zuercher and Lynch in the development of Sonargard. "The system," he says, "fills a safety gap left open by human error." "Even the most alert lifeguards at the safest pools can have problems noticing swimmers going under," Ellis noted, "particularly in the case of 'quiet drowners' — swimmers who suffer a heart attack or seizure and simply sink below the surface without a struggle."

"The chance of a guard catching that person in time to be of any use is pretty remote," Ellis cautioned. "Once a person goes underwater they are almost impossible to detect."

"The Sonargard system is a time gain. It enables the lifeguard to react."

Ellis warns pool owners that the very advantage of having the system can be a drawback if lifeguards are lulled into thinking a sonar device will do their work for them.

"Administrators have to be careful their staff don't rely too heavily on it," said Ellis. "It's a safety enhancement, but it can't save — it can only detect a person. Swimming pools still require professionally trained lifeguards."

After overcoming initial glitches at the Columbia Swim Center, the sonar system is now working smoothly, according to John C. Herdson, swim center director. "The system is unobtrusive," Herdson says. "You don't realize the system's monitoring capabilities are operating until a swimmer has trouble." At Columbia, which has never had a drowning, the system has yet to be triggered by an actual swimmer, although lifeguards test it every day using a mannequin.

A side feature of the system is a nighttime mode, which can monitor the entire pool after hours to detect intruders and alert police or other security people.

"That feature," Zuercher says, "seems to appeal as much, or more, as the daytime safety feature among pool owners inquiring about the system." Eventually, Zuercher believes the system has a future in the backyard pool market.

Insurance Executives Endorse Sonargard

William McCarthy, President of CMG Insurance Services in Virginia Beach, Virginia, said he is "100 percent behind the system" and will offer clients who install Sonargard as much as a 50 percent savings on their wave pool premiums. The company insures about 20 facilities that operate wave pools.

John Naughton, Sr. of Naughton Insurance, Inc. in Providence, Rhode Island, said he is urging his clients to install the system. "I think it's very valuable — we're recommending it," he said. "The system speaks for itself. Parks may see a discount in their premiums by installing the system," he added.

Zuercher states the cost of a system can range from about $28,000 to about $55,000, depending on the size of the pool. Installation costs, which each pool subcontracts, are likely to average around $3,000. Sonar International supervises the installation of each system and handles the start-up and calibration of the equipment.

ABOUT THE AUTHOR: If you're interested to receive more information on Sonargard's innovative safety features for your local pool, contact Mr. Gary Zuercher, Sonar International, Inc. — 46 South Glebe Road, Suite 100, Arlington, Virginia 22204. Telephone 703/797-0707.