Friday, August 12, 2016

Retaining Underwater Emergency Skills

Whether you’re a new diver or experienced, you must retain and periodically refresh the underwater emergency skills you learned in your entry-level scuba course. Although preventing emergencies is of course far preferable, and these situations are rare, it’s nonetheless crucial to react properly. If it’s been a while and you can’t remember some of these skills, then you’re probably due for a refresher course. The PADI Reactivate program is available digitally and is prescriptive-based, so you can refresh specific theory sections. Afterward, connect with a local PADI professional for in-water skills remediation.

Alternate Air Source Use

Most divers’ worst fear is to find themselves out of air. Keep a watchful eye on your air supply to avoid this, particularly if you’re overexerted or diving in currents. If you do find yourself so low on air that you cannot make it to the surface, you’ll ideally signal your buddy that you’re out of air (most agencies agree on using your hand to slash across the throat) and take their alternate air source, often referred to as the secondary or octopus.

If they’re diving with an AIR2 system, you’ll breathe from their primary second stage. Then you’ll secure right arms in the Roman forearm handshake positon or grip each other’s BCDs, signal to ascend while holding your inflator hoses up to vent off excess air, and swim slowly and calmly to the surface. Upon surfacing, the out-of-air diver will kick to keep their head above water while orally inflating their BCD (by depressing the deflator button while blowing into the inflator hose) to establish positive buoyancy. If necessary, the out-of-air diver can also ditch their weights at the surface.

Controlled Emergency Swimming Ascent (CESA)

Often, buddies don’t stay right next to each other on a dive. If you’re the out-of-air diver, you may not be able to locate your buddy for air sharing, which means you may need to practice a contingency skill known as the Controlled Emergency Swimming Ascent (CESA). Usually, you’ll know that you’re out of air as you draw in the last breath from the tank. This feels similar to taking the last sip of a drink through a straw. If you’re practicing a CESA, simply swim to the surface while making a continuous exhalation or “ah” sound.By doing so, the expanding air from the lungs can vent off and prevent a potential embolism. Remember to vent off expanding air from your BCD as well.

You can comfortably achieve this contingency skill from depths of 30 to 40 feet (9 to 12 m) because as the diver ascends, the remaining air in their lungs continually expands. This allows them to continually exhale. Once at the surface, the out-of-air diver can ditch their weights to establish buoyancy and also orally inflate their BCD. Again, if you check your SPG regularly and stay close to your buddy during your dives, this should be  and unnecessary contingency.

Breathing from a Free-Flowing Regulator

If well-maintained and serviced annually, most regulators’ first and second stages are quite reliable and unlikely to fail on a dive. However, any device made of moving parts has the potential to malfunction, and if this happens to a regulator, there is the possibility of an air free- flow. Because of the way they’re engineered, regulators are designed to be ‘fail-safe,’ and so will always deliver air, even in an excessive manner. In this scenario, you must simply maintain a firm hold on the regulator’s second stage, and either use one hand to partially hold the second stage/mouthpiece in the mouth or use both hands to hold the mouthpiece peeled back.

Either way, you can sip the air from the mouthpiece and allow the excessive free-flowing air to vent off. Then, ascend to the surface while breathing the rapidly depleting air from the tank. I prefer to have the second stage partially in my mouth and controlled with the right hand. That way I can use my left hand to vent expanding air from my BCD.

This contingency skill is effective from depths of 60 feet (18 m) and shallower, as beyond these depths the air supply may be depleted before a diver can make it to the surface. Again, a nearby buddy should be able to provide assistance should this occur. Other methods of prevention include: annual servicing of the first and second stages; cleaning the regulator and second stages thoroughly after dive, particularly in salty, sandy and silty waters; and using environmentally sealed first stages in cold water below 50 F (12 C). If you’re diving in cold water, also take care not to purge the second stage for very long.

No-Mask Swimming

Of all the new motor skills taught in entry-level dive courses, swimming with no mask, or the removal and replacement of a mask underwater, is the one that students struggle with the most. As experienced divers, we often forget how alien it can feel to breath underwater; yet without a mask, even experienced divers may find it challenging to maintain good breath control. As with many of the contingencies above, stay relaxed and focused to breathe without a mask.

If your mask should become dislodged for whatever reason during a dive, breathe in and out through the mouth, or in through the mouth and out through the nose. Calmly look around with your eyes open for the mask. If you cannot find and replace it, and cannot get your buddy’s attention for help, then calmly swim to the surface, breathing normally and venting expanding air from the BCD.

Practice will help alleviate any discomfort you may feel while breathing without a mask underwater; after repeated practice, many divers even claim that the exercise leaves them with a Zen-type feeling. To keep from losing your mask in the first place, don’t get too close to kicking divers. Avoid rental masks, and inspect your mask strap on a regular basis and change it out if it’s worn, chafed or brittle. Also, don’t tighten your mask strap too much. This wears the strap and places undue tension on its attachment points, which could make them prone to breakage.

As the saying goes, an ounce of prevention is worth a pound of cure. Make sure to monitor your air supply regularly, clean your equipment after each dive, inspect it prior to each dive, and have it serviced annually. Finally, make sure to stay close to a buddy and maintain regular communication, as mentioned.

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