Gray Around the Gills

With the Babyboomers getting up in years and developing bad backs, creaky knees, and reduced endurance, the question arises: when is one too old to dive? Duke University Medical Center researchers have concluded that as long as older divers remain healthy, the gradual decline in pulmonary function that comes with age isn't significant enough to beach them.

Using Duke's research hyperbaric chambers, the researchers studied the effect of age on the body's ability to balance oxygen and carbon dioxide levels under pressures experienced during normal dives. Carbon dioxide retention is a major safety issue for divers, particularly during heavy exertion and with high breathing resistance either from the regulator or due to lung disease. It can cause mental confusion, seizures, and even loss of consciousness while diving, the researchers said.

"We found that even at a depth of 60 feet with moderate exercise, healthy older people experience increased levels of retained carbon dioxide that was statistically significant from at the surface, but clinically insignificant compared with younger subjects," said lead author Heather Frederick, M.D., an anesthesiology resident at Duke.

Richard Moon, M.D., senior member of the team and clinical director of the Duke Center for Hyperbaric Medicine and Environmental Physiology, added, "Even while exercising, the older group performed similarly in all measures as the young people. It was a real shock to me that they did just as well as the younger participants."

But there are some caveats.

For one thing, the Duke study focused only on carbon dioxide retention and not on decompression sickness. Susceptibility to DCS increases with age, so older divers would be wise to follow conservative practices such as avoiding repetitive deep dives and rough conditions. Take up less taxing interests (such as photography). And breathe Nitrox while keeping the dive computer in the air mode.

Ernest Campbell, M.D., (www.scuba-doc.com) says, "To my knowledge there is no specified age limit to sport diving. Chronological age and physiological age can differ markedly, and each individual ticks to his own genetic clock. This having been said, most elderly divers are not capable of sustaining the work load required by all but the least physically demanding dives. The majority of elderly divers do not exercise regularly or adequately. Physical training can definitely minimize the decline in physical capacity in older divers."

Older divers have a higher incidence of chronic ailments such as cardiovascular disease and chronic lung disease. Arteriosclerosis affects the blood flow to the brain, heart, kidneys, and limb muscles and their functions. Campbell suggests that "Appropriate screening evaluations of the heart and coronary arteries with exercise testing is useful in older divers before instituting a diving program." Besides strength and endurance, flexibility is important when maneuvering in and out of the water.

Ronald T. Garry, M.D., of Harvard Medical School, recently surveyed 99 active divers aged 70 or over (including some Undercurrent readers). Despite multiple medical problems, 99% of respondents rated their health as "excellent" or "good." They took an average of 4.3 medications per day, but only 4 percent felt their meds had a negative effect on their diving ability. A history of diving-related injuries was reported by 16 percent of respondents, with 75 percent of the injuries being middle ear barotraumas. The mean age at certification was 49.5 years, and 29 percent were certified at age 60 or older. They had an average of 24 years of diving experience, performed 52 dives in the previous year, 248 dives in the last five years, and 1314 lifetime dives per person. The vast majority (73 percent) felt that they were better divers now than when they were younger.

One survey respondent, a 74- year-old male diver from Boynton Beach, FL, said "I still dive five dives a day on live-aboards. I find going up ladders in rough waters difficult, but that too has never been easy."A 72-year-old female diver from All continue to do so. However, there are two qualifications: no extreme or frequent deep diving and no strenuous diving, such as in excessive heavy current."

A 74-year-old male from Albia, IA, who takes pride in keeping up with other divers on live-aboards said, "I get in shape for a dive trip by working up to swimming one hour laps with fins on." And a 75- year-old male from Kennett Square, PA, said that although "age has not reduced my comfort or confidence in diving, diminished agility and range of motion have necessitated some adjustments in the strenuousness or difficulty of dive activities undertaken."

Dr. Campbell points out that some savvy older divers arrange for a personal dive guide to help them suit up, don gear, manage their entrances and exits from the water, and accompany them during the dive. "The problem," says Campbell, "comes in getting us old GCFD's (geezer-codger-fogy-duffers) to recognize when the time comes to ask for help!"

If you're not too macho to seek assistance, try looking for a dive operator that offers what many choose to call valet diving service. In the next issue, we'll define valet diving and give you a list of people that specialize in it.

-- Ben Davison