THE LAST GASP

Out- of- air emer­gen­cies are the most com­mon cause of div­ing fa­tal­i­ties; here’s how to avoid catas­tro­phe

Scuba Diving - - TRAIN - BY ERIC MICHAEL ERIC MICHAEL is a for­mer ed­i­tor-in-chief of both Scuba Div­ing and Sport Diver magazines, a vet­eran Scubalab test-team diver, and author of Dive Hacks since 2015.

Run­ning out of air un­der­wa­ter is a diver’s worst night­mare. You draw on your sec­ond stage, ex­pect­ing that sweet, lung-sat­is­fy­ing sip of air — and get noth­ing. It’s a ter­ri­fy­ing emer­gency that none of us should have to ex­pe­ri­ence. How­ever, ac­cord­ing to Divers Alert Network, one of the world’s fore­most cen­ters for re­search on un­der­wa­ter emer­gen­cies and in­juries, run­ning out of breath­ing gas is the most com­mon dive in­ci­dent, and the No. 1 cause of div­ing fa­tal­i­ties.

The sources of out-of-air emer­gen­cies are nu­mer­ous and var­ied. Com­mon com­pla­cency or too much task-load­ing can dis­tract a diver from mon­i­tor­ing his or her gas sup­ply un­til it reaches a dan­ger­ously low level. Mal­func­tion­ing equip­ment, such as reg­u­la­tors, hoses and O-rings, can cre­ate dis­as­trous com­pli­ca­tions at depth. Tests have shown that a free-flow­ing reg­u­la­tor or rup­tured hose can drain an 80-cu­bic-inch cylin­der in less than three min­utes, de­pend­ing on depth. Typ­i­cally, divers have pre­cious lit­tle time to deal with this sit­u­a­tion be­fore it turns dire. All too often, they be­come a statis­tic.

“At least once a year I see some­body run out of air un­der­wa­ter,” says Becky Ka­gan Schott, a Penn­syl­va­nia-based tech­ni­cal and CCR in­struc­tor, cave en­thu­si­ast, and Emmy Award-win­ning un­der­wa­ter cin­e­matog­ra­pher. “No mat­ter what type of dive you’re at­tempt­ing, whether it is recre­ational or tech­ni­cal, and no mat­ter what your ex­pe­ri­ence or level of cer­ti­fi­ca­tion, it can hap­pen to any­one.”

For­tu­nately, many of these ac­ci­dents can be pre­vented. Through ad­vanced train­ing, reg­u­lar equip­ment main­te­nance and mind­ful dis­ci­pline, divers can in­crease their odds of avoid­ing — and sur­viv­ing — an out-of-air emer­gency.

“My grand­fa­ther used to tell me the best way to deal with a prob­lem is to not have it in the first place,” says Edd Soren­son of Cave Ad­ven­tur­ers in Mar­i­anna, Florida, a tech­ni­cal and re­breather in­struc­tor who also is a highly ex­pe­ri­enced cave search-and-res­cue ex­pert. “At first that sounded re­ally stupid, but now I use it in ev­ery one of my classes.”

Con­sider this ex­pert ad­vice to min­i­mize your risk of run­ning out of air un­der­wa­ter.

PAY CLOSE AT­TEN­TION

Out-of-air emer­gen­cies can oc­cur due to sim­ple neg­li­gence. Skip­ping a pre­dive buddy check, ig­nor­ing ob­vi­ous equip­ment is­sues or for­get­ting to turn on your air be­fore you drop can all lead to dis­as­ter. Schott and Soren­son preach sit­u­a­tional aware­ness.

“You see too many times peo­ple get­ting into cur­rents, div­ing a lit­tle deeper than they’re used to, or be­ing dis­tracted with a cam­era and get­ting in trou­ble,” Schott says. “One of the big­gest things I re­in­force with my stu­dents is be­ing self-aware, and al­ways watch­ing your gauges.”

When divers suf­fer a lack of sit­u­a­tional aware­ness and some­thing bad hap­pens, stress can es­ca­late quickly — and turn deadly.

“When you’re un­der stress, you can ex­pe­ri­ence what’s called cog­ni­tive nar­row­ing — you don’t have that big-pic­ture think­ing any­more,” Soren­son says. “We had an in­ci­dent in a cave where the diver had three func­tion­ing reg­u­la­tors and three cylin­ders filled with more than 300 cu­bic feet of gas, but his brain told him he was out of gas. With cog­ni­tive nar­row­ing, he just pan­icked and at­tacked his buddy.”

Be­ing mind­ful of your sur­round­ings and sit­u­a­tion can save lives — es­pe­cially yours.

LEARN TO DEAL

As divers, we train to deal with com­mon emer­gen­cies. But too often, we let those skills grow rusty. By prac­tic­ing the pro­to­cols you’ve learned to man­age outof-air emer­gen­cies, you’ll be far bet­ter pre­pared if it hap­pens to you.

“In­stead of re­act­ing, many divers tend to freeze or panic,” Schott says. “Those sit­u­a­tions could be avoided if peo­ple prac­ticed skills more often. It’s a great idea to go out with your dive buddy and do emer­gency drills so you can re­act faster.”

“Most divers prob­a­bly haven’t prac­ticed air-shar­ing tech­niques since they fin­ished their open-wa­ter class,” Soren­son says. “No­body wants to go out and do a work dive, but there’s al­ways that three-minute safety stop to prac­tice. You’ve got to be there any­way, why not do some­thing that could one day help save your life or that of your friend?”

Soren­son also ad­vises never to skip a pre­dive buddy check, and fo­cus par­tic­u­lar at­ten­tion on pre-breath­ing all of your air sources. In ad­di­tion, learn­ing hand sig­nals that iden­tify po­ten­tial air-sup­ply haz­ards is a smart pre­ven­tion method.

“For cave div­ing, we have an en­tire set of hand sig­nals” to iden­tify po­ten­tial gas emer­gen­cies, he says. “One of them is plac­ing your in­dex fin­ger above your thumb and lightly mov­ing up and down to in­di­cate to your buddy that they have bub­bles com­ing out of a hose or other piece of equip­ment. If some­thing on my setup is bub­bling that I can’t see but you can, that’s some­thing I need to know.”

DOU­BLE DOWN ON RE­DUN­DANCY

For tech­ni­cal divers, re­dun­dant sys­tems are fun­da­men­tal. If an air source mal­func­tions, hav­ing a backup will save your life. Recre­ational divers should con­sider this safety net as well.

“Car­ry­ing a pony bot­tle just for emer­gen­cies, es­pe­cially on deeper dives, can be a re­ally good op­tion,” Schott says. “Hav­ing more gas in case you have a prob­lem and aren’t close enough to your buddy can re­ally make a dif­fer­ence in an out-of-air emer­gency.”

For divers con­sid­er­ing adding an al­ter­nate air sup­ply to their kit, Schott rec­om­mends at least a 19-cu­bic-foot cylin­der that can be strapped to a pri­mary tank, with the sec­ond stage ar­ranged around the neck on a neck­lace.

“Div­ing twin cylin­ders or learn­ing to dive side­mount of­fers a lot of ad­van­tages for your safety,” says Soren­son. “Div­ing an air-in­te­grated com­puter is nice, to have that pres­sure data right there on your wrist, but divers should also have an ana­log pres­sure gauge as a backup.”

KNOW YOUR SAC RATE

Be­yond equip­ment is­sues, some out-ofair emer­gen­cies are just that — the diver sim­ply used all of his gas sup­ply be­fore the end of the dive. Poor plan­ning is typ­i­cally the cause, so learn­ing to cal­cu­late your sur­face air con­sump­tion (SAC) rate — and us­ing it to plan your dives — can help pre­vent dan­ger­ous mis­takes.

“I re­ally en­cour­age peo­ple to learn how to cal­cu­late their SAC rate so they can fig­ure out how much air they’re go­ing to need to do a cer­tain dive, while al­low­ing for un­ex­pected chal­lenges that might force them to use more gas than nor­mal,” Schott says. “You might be sur­prised that what an 80-cu­bic-foot cylin­der holds is just not enough gas.”

“Ev­ery­body should know how to cal­cu­late their SAC rate be­cause if you’re div­ing in the ocean, there can be cur­rents and other fac­tors that will af­fect the amount of gas you’re con­sum­ing,” Soren­son says. “If you do it prop­erly, it’s a sim­ple cal­cu­la­tion. I teach it to all my cave stu­dents, and I have them do it on each and ev­ery dive. It builds self­con­fi­dence and makes for safer div­ing.”

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