Four Factors That Reduce Your Risk of DCS

Peter B. Bennett, founder of Divers Alert Network and now executive director of the Undersea and Hyperbaric Medical Society, gave a seminar at his organization’s annual meeting last fall titled “Safer Ascent Concepts for the Recreational Diver.” He talked about the four factors that could help divers make safer ascents and therefore avoid decompression sickness (DCS). Here’s a synopsis of his presentation.

DCS risk may be affected by the depth of the dive, dehydration, obesity, age, water temperature, degree of exertion, etc. But exercise, water temperature, Nitrox and safety stops may help to make ascents safer.

Exercise 24 hours or even two hours before a dive has been shown to significantly reduce vascular bubbles postdive. However, exercise during a dive leads to increased risk of DCS, while exercise during ascent appears to decrease risk. But exercise after the dive increases the risk of DCS.

If a diver is warm during the dive and then becomes cold during ascent, DCS risk increases. But if the diver is cold during the dive and warm on ascent, the risk is lower.

For safer ascents, the diver should dive nitrox but ascend using an air table.

A shallow safety stop at about 15 feet for three to five minutes significantly decreases vascular bubbles and is now widely used by divers. Recent research has also shown a deep safety stop for two-and-a-half minutes at half the absolute depth can also significantly reduce vascular bubbles post-dive at 82 feet. Whether this also will be the same for all recreational divers at all depths, however, remains to be established, as does whether this will reduce DCS.