Lionfish Stings

STEPHEN FRINK

Nitrox is often used to extend dive times but can alternatively be used to reduce DCS risk if dive times are kept within the no-decompression limits of air dives to the same depth. Opposite: A thorough buddy check before every dive reduces the risk of forgetting important equipment and serves as a reminder to adjust gear for comfort and security.

When planning a trip, consider how your skills, experience and fitness match up to environmental conditions and requirements of the dive destination. Reassess your risks before each dive, taking into consideration the actual conditions. Rough water, poor visibility, currents and unfamiliar surroundings can present significant challenges to divers. When combined with gear troubles and poor physical fitness, these factors really set up divers for failure, which in the diving environment may be fatal.

When at a dive site for the first time, seek the assistance of local professionals in assessing dive conditions and risks. In addition, dive professionals may help you assess your own abilities and limitations and provide the training necessary to ensure your skills match the environment.

SAFER DIVING PRACTICES

Once at the dive site, what can you do to enhance your safety, reduce your risk of decompression sickness (DCS) and further stack the deck in your favor? While the overall risk of DCS is very low, it still occurs and is worth avoiding. Some simple steps you can employ on your next trip may make a difference.

For divers, DCS results from the formation of nitrogen (or other inert gas) bubbles within tissues and blood vessels secondary to a reduction in ambient pressure. Gas dissolved into liquid (bodily tissues and blood) at depth may come out of solution and form bubbles either during or after ascent. Bubbles can cause tissue inflammation and compromise blood flow. The amount of dissolved nitrogen is proportional to the depth and duration of a dive, so decreasing these will reduce the risk of DCS. Longer surface intervals, slow ascents and prolonging the time spent at shallow depths will promote off-gassing — the safe elimination of accumulated inert gas.

Enriched air nitrox (EAN) has less nitrogen than air, so its use by divers results in less nitrogen absorption than similar profiles on air. It should be noted, however, that the safety margin enjoyed with nitrox is achieved only by diving air tables or equivalent computer settings. When divers set their computers for nitrox with the intention of extending bottom time, this safety margin is lost. The use of nitrox comes with unique safety concerns such as oxygen toxicity and requires proper training.

An additional factor that may impact the incidence of DCS is poor hydration. Hydration has gained attention

for its potential role in reducing DCS risk and for its adjunctive use in medical management (use of IV fluids along with oxygen or hyperbaric oxygen therapy). While hydration alone does not make up for or counteract provocative dive profiles, suboptimal hydration status — often associated with alcohol intake and hot climates — may be associated with increased DCS risk.

MENTAL PREPARATION

Mental preparation is critical for safe diving. Fear, apprehension, fatigue and severe anxiety can compromise decision-making abilities. If you aren’t feeling up to diving or if the conditions or goal of the dive frighten you, don’t go.

DIVE PLANNING

With the widespread use of dive computers, dive planning has largely become a lost art. While these incredible little machines do a lot to keep us informed underwater, it is important to remember that the limits they impose are based on mathematical algorithms that have not been validated by experimental research. In addition, each of us will have a varying degree of susceptibility to DCS throughout our lifetimes and from one dive to the next, none of which is accounted for by standard tables or computers. Therefore, the no-decompression limits (and decompression instructions in technical-diving computers) should be viewed as guidelines and not representative of absolute or established boundaries that are “safe” so long as they aren’t violated.

HAVE A BACKUP PLAN

You’ve modified your dive practices and added layers of safety, but you want additional preparation and security because you know things can still go wrong.

In addition to personal health, the prepared diver should consider the financial impact of emergent care and evacuation. Dive accident insurance provides financial safety and helps with the high cost of evacuation, transportation and medical care. As with any insurance, know what your policy covers before you leave. Don’t rely on folklore, your dive shop or your instructor. Read the policy, and understand the true nature of your coverage and what exclusions exist. Before buying dive accident or trip insurance, consider where you will be

“When planning a trip, consider how your skills, experience and fitness match up to environmental conditions and requirements of the dive destination.”