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Decompression sickness (DCS) occurs

While a diver’s depth/time profile is, by far, the most-important factor in decompression sickness risk, other factors that may contribute to individual susceptibility.

The timing and intensity of exercise (also known as workload) during a dive can substantially affect a diver’s risk of DCS. Exertion increases blood flow and its gas carrying capacity. Consequently, exertion during descent and the deepest phase of a dive increases the amount of gas dissolved in tissues and the subsequent decompression stress. Mild exercise during decompression speeds up off-gassing. Exertion immediately following a dive can stimulate bubble formation and increase the likelihood of bubbles passing through the lungs without being filtered out of the circulation.

A diver’s body temperature can influence decompression risk. A warmer body absorbs more inert gas and releases it more readily. Conversely, a cooler body absorbs less gas during descent and releases less during ascent.

Divers using protective suits without active heating should avoid long exposures that may chill them. When using heated garments, a diver should stay comfortably cool at depth and warm during decompression. Staying comfortably warm during decompression and after dive promotes inert gas elimination and reduces the risk of DCS.

Flying after diving increases decompression stress because the pressure in an aircraft cabin is lower than atmospheric pressure on the ground. The recommended guidelines for flying after diving are as follows: • After a single no-decompression dive, a minimum preflight surface interval of 12 hours is suggested. • After multiple dives per day, or multiple days of diving, a minimum of 18 hours is suggested. • After dives requiring decompression stops, a preflight surface interval substantially longer than 24 hours is considered prudent. • Observing surface intervals longer than the recommended minimums helps to further reduce a diver’s risk.

Dive conservatively to help avoid the bends

Poor health and physical fitness can compromise individual safety when diving and may increase risk of DCS. Regular exercise improves fitness and cardiovascular health, which mitigates risk of DCS: • At least two-and-a-half hours of moderate-intensity aerobic exercise per week to achieve health benefits, and five hours per week for fitness. • Muscle-strengthening activities at least two days per week. While individual susceptibility to DCS may vary, every diver can reduce their risk of decompression sickness by ascending slowly from every dive and following recreational diving guidelines. n

DAN Dive Accident Insurance provides up to $500,000 of eligible medical expense coverage for diving, nondiving, and named watersports accidents and injuries.

For more details, see handbooks under Compare Coverage at DAN.org/membership-insurance/dive-insurance. For residents of NY, insurance is underwritten by The United States Life Insurance Company in the City of New York, NAIC No. 70106 domiciled in the state of New York with a principal place of business of 28 Liberty Street, Floor 45th, New York, NY 10005-1400. It is currently authorized to transact business in all states, plus DC, except PR. This summary is a brief description of benefits only and is subject to the terms, conditions and limitations. Coverage may vary by state. AG 12070 For residents of all other U.S. states and the District of Columbia, insurance is underwritten by National Union Fire Insurance Company of Pittsburgh, Pa., a Pennsylvania insurance company with its principal place of business at 1271 Ave of the Americas FL 37, New York, NY 10020-1304. It is currently authorized to conduct insurance business in all states and the District of Columbia. NAIC No. 19445. The issued policy and certificate will contain reductions, limitations, exclusions, definitions and termination provisions. Full details of the coverage will be contained in the issued policy and certificate. Coverage may vary by state or may not be available in all states.