Situational Awareness II

Beyond the Dive

In the Winter 2011 Alert Diver, DAN provided a look at how situational awareness (SA) affects the safety of divers. But divers are actually the beneficiaries of studies conducted on SA not only in the diving arena, but in the aviation, naval and surgical fields.

Recently, Atul Gawande, MacArthur Fellow and general surgeon at The Brigham and Women's Hospital in Boston wrote the bestselling book The Checklist Manifesto. Gawande demonstrates how the constant use of checklists, borrowed from the aviation community, has made surgery safer. Checklists are commonly used in many fields, yet catastrophe occurs even with their consistent use. The following are examples of where inadequate SA or procedural follow-through led to critical errors.
Case Studies
  • Dec. 29, 1972: The cockpit crew of Eastern Airlines Flight 401 is on a normal night "visual flight rules" approach to Miami International Airport. The landing checklist is complete, but the nose gear warning light is on, requiring investigation and a "go around" pattern. The crew fails to monitor the altitude, ignores the low altitude warning light and flies the aircraft into the Everglades. There are 101 fatalities. The voice recorder confirms that the landing checklist was performed correctly, but the National Transportation Safety Board found the crew preoccupied and distracted.

  • Feb. 5, 2009: The Ticonderoga-class guided-missile cruiser USS Port Royal runs aground at Pearl Harbor – resulting in millions of dollars in damage. The accident board found that the navigation crew had failed to recalibrate the navigational system.

  • November 2005: A vascular surgeon marks a patient's RIGHT leg for a combined toe amputation and arterial bypass. This follows the latest safety guidelines, designed to limit "wrong site" surgical errors, techniques embraced by the surgical community. After "scrubbing up," the surgeon walks in to find the nurse prepping the LEFT leg. Fortunately the error was quickly corrected and the operation went as planned. The near miss or "sentinel event" investigation reveals that the verbal and written checklist were completed, yet the prep team still got it wrong.

Though the case studies were generated in the naval, aviation and surgical fields, the impact of lost SA affects people in all walks of life. A goal we might all strive for is to emulate the strategies employed by SA experts, who have implemented with maximum effectiveness the three SA fundamentals (perception, comprehension and projection) described in Alert Diver. Yet the experts are fundamentally no different than you. What they have learned, so can you. Let us first look at common human limitations, and then review some simple countermeasures and strategies that can compensate for these foibles.

Limited short term memory
This is our "working memory." In contrast to our long-term memory, which contains the cumulative knowledge of our education, life, events, etc., our working memory is the computer RAM of our brain. Think of trying to memorize a new phone number. It's just seven digits, yet we often have to write it down or repeat it over and over until we have it stored for ready use. Research shows that we can optimally manage four items at once, after which our performance degrades. This limitation of our short-term memory should prompt us to limit our task number to ensure optimal performance and minimize errors.

Frame Errors
We all are a product of our experiences. This is the "frame" within which we place data and cues to make sense of them. This is an efficient way to leverage previous experiences. In the previously mentioned surgical "sentinel event," the team member was used to seeing an "X" represent the location of pulses in the leg. Years of experience created this frame of reference. Yet in reality, it represented the new practice of "surgical site" marking. This frame error or cognitive bias (misinterpretation of what we see or hear) is all too common, blinding operators to the true meaning of the situation.

Design and Management
These are commonly known as systems or process errors. For example, does the dive boat have a chase boat available? How about additional oxygen supply for treatment of decompression illness? Which crew member is designated to call the Coast Guard? The ability to project consequences is fundamental to good planning.

So it looks like we have too little memory, are susceptible to personal frailties and work in flawed systems, but there are solutions. Let's look at them from an individual and team perspective.
Individual Tips
  1. Minimize multitasking; it is proven to be the worst possible strategy for actually accomplishing any task. Example: Do not assemble your gear during the dive brief. Instead, focus on the dive plan, and make sure you and you buddy agree.

  2. Get into your SA zone.
    • Level I: Alternate your scan of critical data like depth, time, buddy position and pretty fish (you are there to have fun).
    • Level II: Evaluate this information in the context of your dive plan.
    • Level III: Project your current position into the future to see if it makes sense or if changes to your plan are needed due to new information.

    • Look for clues to loss of SA. Is your dive plan off? Is there conflicting data? Do you and your buddy have wildly different pressures on the gauges? Are you not reaching the checkpoints on the plan? Are the conditions more challenging than you expected? Should you be able to see the boat?
Team Skills
The United States Air Force Research Laboratory has found that the best combat teams excel in these three fundamentals of teamwork:

  1. Communicate: Exchange information freely and use closed-loop communication, which means when critical data is passed between two parties, the receiver repeats back exactly what was heard. It may seem a little rigid, but it works and minimizes miscommunication. This is crucial when formulating a complex dive plan or diving in dangerous waters. This is dogma in the public safety diving community.

  2. Cooperate: Maintain a positive attitude; be happy to accept advice and help from others. Make sure they know you want them to have a great dive. This is called "shared cognition" and is a great way to get all the divers on the same page.

  3. Coordinate: Make sure all divers share the goal of that dive. Be willing to step up and help anybody on anything. Monitor the performance of your team and offer assistance if somebody is over tasked or needs help.

Finally, develop what NASA astronauts call "courageous self-leadership." Always strive for perfection. Do not fall into the complacency trap. Just because a regulator is working fine is no reason to skip its annual service. After all, the Challenger O-rings had always worked before in cold weather. If you don't think the head count is correct, say something. You are not being foolish by raising your hand or noting inconsistencies, you are being the diver we all want as a buddy.