Diver Down: The Forces of Habit

Habit and Complacency Can Kill

Diver Down: Dive Accidents, Close Calls and How You Can Avoid Them

Each Diver Down case presented on Seaduction.com is written by the author of "Lessons for Life" the #1 column at SCUBA Diving Magazine from 2001-2009.  Each case is based on a real incident that has been thoroughly investigated through official sources and the accounts of participants and witnesses. Names and some minor details have been changed to protect victims and their families.

By Michael Ange

It had been a stressful dive and John was decompressing now in a strong current with very limited visibility.  It took substantial effort to hang on to the line and there was a fair amount of task loading with gas switches, holding the line and trying to position so that you would not interfere with a buddy.  John switched to his hyperoxic gas, his regulator hose somehow got tangled in his gear, and as he moved in the current, the regulator was pulled out of the mouthpiece.  John breathed in and was astonished to get a solid breath of water.  He immediately signaled to the closest diver, reached in, and grabbed a regulator.  But, was unable to purge it.  He was desperate for air now. 

The Divers

John was an experienced recreational instructor with several hundred logged dives in varying conditions.  They included the warm tropical dives that everyone likes to do, but also a number of cold-water dives in poor visibility rounded out his experience.  He had reached a plateau in his career as a recreational instructor and had decided to move into the realm of technical diving.  He had transitioned into the twin cylinders with stage configuration fairly well, though he recognized that he was still controlling his equipment through force instead of finesse.  His desire to continue his development led him to a third technical diving class.  John was in excellent health with above average water skills and extensive underwater experience.  He was one of a four-man team which included a technical instructor, a technical instructor candidate and his buddy, also a technical diver and recreational instructor.

The Dive

It was the fifth day of a six-day dive week in a popular diving location.  The first dive of the day to around 120 feet was not going well.  The objective was penetration of a popular shipwreck to complete skills.  The dive started on a bad note with the team getting separated due to a failure to enter the water as buddy teams.  When John failed to make the 20 fsw rendezvous point the instructor had the remainder of the team surface hoping to find John on the surface.  John had not surfaced, since visibility was poor the entire team descended the line to initiate a missing diver sweep along the deck of the ship.  John was located very quickly as he swam toward the designated descent line.  He had somehow managed to descend on a different mooring line.  After reconnecting the divers completed sub-surface gear checks and an s-drill where they encountered some minor but easily squared away issues with equipment.  With everyone squared away and OK signs all around the instructor decided to let the divers continue the dive.  The dive team completed a complex multi-deck penetration with minimal issues inside the wreck but the dive was just starting to get interesting for John as they exited.  Conditions continued to worsen and they exited the wreck with less than four feet of visibility and a current that was approaching three quarters of a knot. 

The Accident

The divers exited the wreck, secured reels, and gathered at the base of their ascent point.  Checking gear and decompression status, the four-man team which included a technical instructor, an instructor candidate, and John and his buddy.  As they ascended the line, the divers completed a deep stop and moved on to a relatively short decompression schedule with a short stage stop at 30 feet and stops at 20 and 10 feet planned.  As the divers approached 20 feet, they completed a gas switch it was shortly after this that John managed to separate his second stage from his mouthpiece.  This was the task loading that nearly took him over the edge.  Signaling his Instructor that he was out of gas, he reached in and grabbed the Instructor’s regulator before the long hose could be unwrapped.  Pulling it between the stage and the BCD, so that the hose could not be extended.  Struggling to get the regulator in his mouth, he soon discovered that he was not familiar with the design and was unable to purge it.  Much closer to panic now, he spit the regulator out and moved to the next diver on the line.

The Rescue

The Instructor Candidate was next in line and was less than an arm’s reach from the Instructor trainer.  Seeing what was going on, he had a regulator ready and John was able to get what was by this time a much needed breathe of air.    After a few breathes, it dawned upon him that he had two perfectly functioning regulators hanging around his own neck and that the gas in his back mounted cylinders was exactly the same as the gas in the back mounted cylinders he was breathing from.  The Instructor Candidate helped him to sort out his gear, switched him to his own regs, and he was able to complete his decompression stops on his back gas plan without incident. 

Analysis

 John’s experience is a prime example of how the fallacy of experience can get you into significant trouble.  Divers reach a point where their confidence in their skills can actually become dangerous.  For example John and his buddy had adapted a procedure of entering the water at relatively the same time but joining up as a buddy team at 20 fsw due to the poor surface conditions.  This a common practice for technical dive teams, however the intent is to enter with your buddy and have the buddy teams assemble at 20 fsw.  John was also separated from his buddy during the ascent phase of the dive.  The procedure for any dive is to remain approximately an arms-length from your dive buddy at all times.  For dive instructors these little procedures slip into the abyss of complacency fairly easily and usually without notice – until something happens.  In this case, the reg set John was familiar with using in several simulated emergencies was hanging just where it should be around the neck of his dive buddy.  Unfortunately, the buddy was separated from John by a barrier of two other people when he needed to access that gear. 

Divers also reach a point where reflex skills can override rational thought with negative consequences.  John had taught dozens and dozens of students to obtain a buddy’s regulator and share gas when they had any kind of gas failure in their own system.  This well engrained thought process led him to a reflex reaction when his own gas system failed.  As a result, he moved several feet up a line after inhaling water, attempting to grab another diver’s regulator, when there was a fully functioning source of gas hanging less than four inches from his mouth.  By the time he reached his Instructor, he was teetering on the edge between control and loss of control.  Moreover, although he had seen Poseidon regulators before, the process for purging the slightly different design was beyond his grasp in the situation he found himself in.  He further compounded the problem by grabbing the regulator and pulling it out instead of allowing the Instructor the second that would have been required to properly deploy it.  John was well into the early stages of panic when he finally got something to breathe and regained control. 

As divers, we all dive inside of a comfort zone and the cumulative effects of small stressors can move us outside of that zone.  In an ideal world, we would all dive in the middle of the bubble and we would all recognize that the bubble called a comfort zone can be popped by the slightest little nudge if we get too close to the wall.  This is precisely what John encountered.  He was learning new skills, although he was very experienced as a diver, he had much less experience using a technical gear configuration.  The dive had started badly with group separation and minor gear problems for the team.  Although these issues were resolved, they were part of the accumulation of stress.  As the divers ascended, he encountered some of the most difficult conditions he had ever encountered in tech gear.  Just the process of staying on the line and maintaining stop depth was a stress factor.  Finally, the trigger was the regulator coming apart – a situation that he could have easily solved and probably had solved before, but this time he was so close to the edge of his bubble his comfort zone collapsed.  He had made a number of gas switches back and forth in his previous training and during the training in the course he was taking.  Furthermore, he was well versed with dive equipment, how it functioned and the procedures to use with a similar regulator malfunction.  In virtually any other circumstance, this problem would have been a minor blip that would have barely gotten a mention on the dive boat for this diver.  But, as they say, the dive never gets better unless you can fix it and for a little stress just add water.  John pushed the edge of panic, but his training and experience in the water, kept him just barely on the side of control.  In the post dive discussion, he admitted that he had lost it and didn’t think to go back to his primary regulator.  He was able to thoroughly debrief the Instructor Trainer on exactly what went wrong and he was able to do this immediately after the dive.  This demonstrates that there was no deficit in his knowledge base or his procedural practice.  It is also evidence, however, that panic is an equal opportunity syndrome and that anyone under the right circumstances is susceptible.  Comfort through repetition, realistically simulated practical exercises and an expanding knowledge base are the elements to increase the size of the comfort zone.  The bigger the bubble, the less likely you are to pop it.  Perhaps this is one of the most important lessons for any diver to learn because these realizations are the best guard against complacency.

Lessons for Survival

·         Stop think and act.  We learn it from the beginning level of scuba.  Unfortunately, it is easy to leave out the middle part of this equation.  Failure to think through your actions can make them ineffective turning a small problem into a major catastrophe.

·         STAY WITH YOUR BUDDY.  It is kind of like that skill we learned in kindergarten, everyone knows it, everybody knows it works, but sometimes we know it so well that we decide not to use it.  DAN stats and a number of recent high profile fatalities or near fatalities in our industry prove that leaving your buddy, no matter how experienced you are or how mundane the dive, is a really good way to become a statistic.

·         Be reflective, not reflexive.  In some cases, a knee jerk response to a common problem will have the desired outcome.  I rarely encounter those situations.  The core response skills provide a foundation which when added to a quick thought process create a solution.  Your actions should reflect a response to the real problem, not necessarily a problem you saw on a video or read in a book.

·         Over confidence kills.  Although this was not John’s issue, it is a common issue amongst divers in John’s experience range.  They become so confident that things will go well or that they are prepared that a major problem becomes a major blow that is more difficult to recover from. 

·         Regulator hoses are not load bearing equipment.  If you are having to bite down hard to keep a regulator in your mouth, there is a problem.  Find it immediately, before you damage the hose or the second stage attached to it.