Flotsam & Jetsam

The November/December Issue: Just a reminder that the Chapbook serves as the November/December issue. It will be mailed in early December and the January issue will be mailed in late December.

Exercise During Decompression ?: An experiment was performed at Canada’s Defence and Civil Institute for Environmental Medicine involving 140 man dives to 45 meters for 30 minutes. There were four study groups: inactive on the bottom and during decompression; inactive on the bottom but active exercise on decompression; active exercise on the bottom and inactive during decompression; active exercise on the bottom and on decompression. Active exercise brought the heart rate to 130- 150 beats per minute (mild, not vigorous exercise) for five minutes followed by rest for five minutes. In comparing the four groups, they found no differences in bubbling between the inactive during decompression groups and no difference between the active during decompression groups. However, there was a statistically significant difference between the inactive during the bottom time and the active during decompression groups, showing a much lower risk of decompression illness, i.e., exercise during decompression reduced bubbles and reduced the risk of decompression illness. But, exercise during decompression does not mean you can decrease your decompression time.

From a presentation at the Great Lakes Chapter of the Underwater Hyperbaric Medical Society, by Louis Jankowski, Ph.D., Professor at McGill Universities in Clinical Exercise Physiology. He is also an NAUI Course Director.

We erred:Reader Rick Murchison wrote that “in your article on children diving, you say that under SSI ‘Children 10 to 12 may receive a junior open water certification with certain limitations. Once they turn 12, they may upgrade to a regular open water diver. ’ That’s not so. They are still Junior Divers until age 15, when they may upgrade ---- the 10-11 year-old junior diver may dive only with a parent (or legal guardian) or an instructor, and only to a depth of 40 feet; 12-14 year-old junior divers may dive with any certified adult diver but are restricted to 60 feet. This is a far cry from ‘regular open water diver’ and recognizes that those under 15 are still children requiring supervision.” Thanks Rick, for catching our error.