Giving Up: Why the Coast Guard Quits Looking

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It’s a call that always comes sooner than hopeful relatives are prepared for. Loved ones pin their hopes on one last flight, and the Coast Guard sector commander — the man or woman responsible for calling off a search — knows it. Now he or she has to tell them that nothing was found, and they are giving up. Deciding to quit a search is the worst part of the job.

When the Coast Guard suspends a search for a missing boater, hearts that were breaking now fully break, and the news is met with more than tears. There is often also anger and confusion. The anger can’t be helped, but the confusion can be. Most people lost at sea stay lost. It’s a harsh reality that the Coast Guard deals with every day. So when the Coast Guard suspends a search, they are never giving up early.

Probability of Survival Decision Aid (PSDA)

The Army is not where you might expect to find answers about sea survival, but it has done most of the work in determining how long a person can survive in the water. A team at the Biophysics and Biomedical Modeling Division at the Army Research Institute of Environmental Medicine created the PSDA, a computer program fed by a complex model of factors on one end, and data about each particular rescue in the other.

The tool was developed to predict survival time by taking into account hypothermia and dehydration as the two main things you need to avoid to survive. Assuming one can stay on the surface or in a raft (or aboard a boat) long enough, survival then is about staying warm first and hydrated second.

There have been improvements to the interface, and the model and predictive data used grow every year, but when compared to actual cases of survival, the PSDA ranges from accurate to generous on the survival times, based on different situations. Which is to say that the models give survivors every possible benefit of the doubt.

A screen shot of the U.S. Army-developed Probability of Survival Decision Aid (PSDA)

A screen shot of the U.S. Army-developed Probability of Survival Decision Aid (PSDA)

What You Are Wearing, Where You Are

Early in the search, the Coast Guard gathers data on the incident and answers questions about the person they are searching for. Then it determines what they might be wearing and gathers data on the environment to feed the models run by the PSDA.

Air and water temperature, relative humidity and wind speed, age, height, weight, even your level of fitness are factored into the model. What you are wearing — drilled down to some very well-researched details — also factors into the PSDA survival engine. The model crunches the data and comes up with three numbers: cold function time, cold survival time and dehydration survival time, all measured in hours. The cold function time is how long a survivor should be able to effectively move (or wave for help or use a radio). The other two numbers are what they are.

The Navy conducts cold-water survival testing using “Nemo,” an anthropomorphic dummy that actually sweats. When placed in cold water in different clothing and life jackets, researchers use Nemo to determine how much protection one piece of gear provides compared to others. So when the Coast Guard asks, “What were they wearing?” those answers are fed into the PSDA and draw on the Navy’s results from Nemo, as well as data from actual case history, to determine the survival time.

Nemo, the U.S. Navy's cold-water test dummy. 

Nemo, the U.S. Navy's cold-water test dummy. 

No Assumptions

The most remarkable thing about the PSDA and how the Coast Guard makes decisions about search times is the extraordinary benefit of the doubt they give to persons in the water without a life jacket. The tool will never assume the most likely cause of death (drowning) in any search case. Regardless of how good a swimmer a person is, what kills people first in almost all water temperatures is cold incapacitation and drowning. The PSDA just assumes that won’t happen and lets the data assume a person is managing to stay afloat. Perhaps the missing person ran across something that floats or managed to have a life ring thrown overboard at them. The Coast Guard will keep searching and assume that flotation was acquired somehow.

Hands down the most difficult part of search and rescue was coming up empty after the last search of a case. Calling in with negative results and heading home was the worst part of the job. Still, I always knew the sector commander had just been given a more difficult task.

Telling survivors that a search is over, along with their hope, is obviously a hard thing to do. But don’t be confused; deciding to quit isn’t a decision the Coast Guard makes without exhausting every possibility. For a deep dive into the PSDA tool and how it is used, download the research papers here and here.



The Wrong Argument - Why Experience Doesn't Matter

No one likes to change when it comes to new rules or regulations that restrict free will. Professionals should decide for themselves what is right or wrong, based on their knowledge and experience, and apply it to operate their vessel safely and effectively. The only problem is just how often that model fails. Mario Vittone explains why experience is a rotten teacher in this week's installment of Lifelines: Safety And Rescue at Sea.


Why Go It Alone?

Self-reliance is one thing many boat owners embrace, but that ethos could get you into trouble, writes Mario Vittone. p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; line-height: 11.0px; font: 39.5px 'Meta Serif Pro'} p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; line-height: 11.0px; font: 9.0px 'Meta Serif Pro'} p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; text-indent: 8.0px; line-height: 11.0px; font: 9.0px 'Meta Serif Pro'} span.s1 {letter-spacing: 0.6px} span.s2 {letter-spacing: 0.1px} T here was a time when leaving sight of land came with a good chance of never seeing it again. Before the invention of the marine chronometer to determine longitude, going over the horizon was a risky move. Even with accurate charts and a watch, the sea remained deadly; so deadly that the raised platforms known as widow’s walks on New England homes got their name from the sea captains’ wives, who would pace their rooftops, looking seaward for ships that never returned. Without VHF radios or radar, anyone who sailed offshore was truly on his own. Self-reliance wasn’t a romantic, Emersonian notion; it was a condition. Sailors had only themselves. I’ve met countless sailors who do their best to hold on to the traditional notion of being on their own out there. They speak of self-reliance as part of the appeal of being far offshore, alone in the world with only their skill and wits to protect them. They speak of it as a decision they made to be independent. When I was working in search and rescue, these sailors were the ones who always called at the last possible minute; but they always called. These are the guys who often say silly things like, “Never step off until you have to step up.” They were the first ones to send hate mail when I suggested that being alone in a life raft without having made a distress call meant a sailor had screwed up (“The Truth About Survival Training,” August 2019). “What about a lighting strike that causes a fire?” one man complained. “I guess you’ve never heard of anyone hitting a deadhead in the middle of the night,” another offered. Those who fancy themselves to be like the sailors of yore said I was wrong. Self-reliance, they wanted; blame, not so much. Now, I’m no sailor. While I do love boats and have spent a few years working on them, the bulk of my exposure to modern boating has been through search and rescue. For a long time, I was only on boats that were in distress following a call for help. Perhaps that skews me to one side of this argument, but given that experience, I believe this: The idea that you are self-reliant out there can get you killed, while the idea that everything is your fault is vital to your safety. We are connected in ways our great-great-grandfathers could never have imagined. Our radios can talk to each other. Our boats have alarms and pumps connected to apps on phones. We do not watch from rooftops for sails on the horizon; we log on to websites for real-time information. We are not alone out there anymore. But, make mistakes at sea, and you will, one way or another, invite people ashore to join you in your “self-reliant” adventure. We must never lose the sense of absolute personal responsibility for our own safety. There are rare situations where lightning strikes and submerged containers cause unforeseeable situations, but they are no reason to abandon modern tools and procedures. We don’t take off our seat belts just because there is only a slim chance that oncoming traffic may swerve into our lane. The answer to the rare disaster we can’t predict in boating is a float plan and communication prior to the mishap. I think the last great gains to be made in boating safety are in how we think about being on the water. If you still believe in self-reliance, then Godspeed, but keep your VHF radio on, if only so that your loved ones aren’t walking the rooftops, hoping for your return.


The High Cost Of Waiting

At sea during an emergency is the absolute worst time to discover what your life raft is or isn’t packed with, or to figure out how to get in and out of it, writes Mario Vittone in this week’s Lifelines: Safety And Rescue At Sea blog.


The Case That Changed Things

After working an incident where an angler and his two sons lost their lives, Coast Guard Rescue Swimmer Mario Vittone changed his focus to helping boaters prepare for the worst. He writes about the case, and his upcoming Boaters University video series, in this week’s Lifelines: Safety And Rescue At Sea blog.