How to Avoid Hypothermia in Search and Rescue Diving

by Dr. Thomas Powell:
ERDI PS diverImagine it is the middle of January. At 2am the call comes in that a vehicle has entered the water with the potential for trapped passengers. As you race to your vehicle, the ice and snow cause you to slip and slide along your driveway. As you arrive on scene with your teammates, you realize that the water temperature is even colder than the air temperature. Despite the harsh conditions, you know that lives may be at stake and you need to enter the water. In search and rescue/recovery diving, divers face many potential hazards. One of the greatest hazards public safety divers may face is hypothermia. There are various methods to reduce the threat of becoming hypothermic, but divers must train in the use of these methods to be prepared when a real mission takes place.

  1. Exposure Protection
  2. The most obvious method of reducing the threat of hypothermia is to wear the proper exposure protection. In the world of public safety diving, dry suits are essential. Dry suits create a barrier of air between the diver and the natural environment. The problem with dry suits is that they often have little or no properties that provide thermal protection. For this reason, public safety divers must consider the use of undergarments. Undergarments come in various weights and sizes designed to provide different levels of thermal protection. The best thing that any dive team can do is analyze the temperatures it faces within the region it operates. Various undergarment weights may be needed to allow for proper thermal protection during temperature changes throughout the year.

    Dive teams around the United States often forego the use of undergarments. Instead divers will wear street clothes or “sweat clothes” underneath dry suits. The problem with “sweat clothes” is that they are often made of cotton, which retains moisture such as sweat. Allowing wet cotton to remain against the skin can cause the diver’s body temperature to drop as the material cools. Similarly, street clothes often provide little or no thermal protection. For these reasons, dive teams should consider looking into the various types of thermal protection designed for dry suit use within the scuba industry. Once undergarments are selected, the divers must train in the use of these undergarments. Differing types of undergarments often have differing buoyancy characteristics and may require weight adjustments for each diver. Similarly, with the addition of extra material, divers need to practice underwater skill sets to ensure capability and comfort.

  3. Reduced Bottom Time
  4. Many public safety divers develop a mindset focused on success. In many cases, this mentality is essential to remain focused and capable when faced with harsh conditions and no visibility underwater. The problem that can arise with this mindset is that divers will often push limits and take unnecessary risks. For this reason, a diver may request to stay underwater longer and increase the risk for the development of hypothermia. Team leaders, supervisors, and even tenders must watch for this attitude and make sure that divers stay within safe limitations. In many cases, the development of maximum bottom times can be developed within team standard operating guidelines to ensure that all divers stay within reasonable time-based dive limits. If these standards are developed, teams must train to perform and enforce time restrictions. Public safety divers must remember that they go on missions to help others, but not to take risks that may add death or injury to an already problematic situation.

  5. Medical Support
  6. In many cases, dive teams do not take advantage of resources located within their communities. These resources may be firefighters trained in hazardous materials decontamination, law enforcement personnel trained in scene security or crime scene investigation, or emergency medical technicians. Medical personnel are critical to the success of any public safety dive operation. If emergency medical technicians or paramedics are available to take baseline physiological readings before divers enter the water, they will have an improved likelihood of recognizing physical changes as divers exit the water. After any diver exits the water and undergoes any needed decontamination, the safest action to take is to have the diver checked out by medical personnel. Professionals of this type can recognize the onset of hypothermia and take corrective actions as needed to ensure diver safety. Emergency medical technicians and paramedics can also help to ensure that divers remain hydrated and intake calories to help fight off problematic physiological situations. In certain cases, medical personnel will even offer heated vehicles as a location for chilled divers to fight off the onset of hypothermic conditions. If medical personnel who are not members of a dive team are going to be used during active missions, they should be invited to partake in training to ensure that all parties will understand how each other will react and perform during a real mission.

  7. Practice and Training
  8. The primary action that any dive team must establish is regular training. Training ensures that divers do not become complacent and that team members and associated parties understand how to act, perform, and behave during real missions. Training evolutions are the perfect time to practice regulated periods of bottom time, interactions with medical personnel, and even skill proficiency using condition-specific equipment. Training and practice will ensure that divers are best protected and that a team understands how to recognize and react to problems that are out of the ordinary such as a diver suffering from hypothermia.

Hypothermia is a condition that can debilitate a diver and his or her team. If a diver goes down, the team may lose a critical member. Similarly, the diver may face a serious personal ailment. Public safety divers must obtain and then maintain the proper equipment needed to fight the potential for hypothermia. These divers must then work to establish a manner in which they can train to best monitor, evaluate, and care for team members in a fashion that best supports operational objectives. More than anything, public safety divers must care for themselves, and work to support the community in which they dive rather than take unnecessary risks that could cause self-harm or injury.

– Dr. Thomas Powell
Owner/Instructor Trainer – Air Hogs Scuba, Garner, NC


Proper Procedures for Interviewing Witnesses

by Tanya Chapman:
incident sceneIt’s 8:00pm on a Saturday evening, you have just sat down in your most comfortable chair after a long day of grueling yard work anticipating a quiet night to relax, you find yourself starting to doze off a bit. Suddenly, you are jolted awake by the sounds of a cell phone ringing, a pager going off or some other form of notification that you are urgently needed to respond to a report of a car in the water with a child still inside.

You rush to gather your necessary equipment, your mind racing on what equipment is needed and available, the safest and most expeditious route to the scene, who needs to be notified, what your actions will be upon your arrival, how you will manage the scene, your manpower, your resources. You arrive and begin to gather the facts of what occurred, where the vehicle entered the water, where it is currently located. You assess the water’s temperature, depth, clarity and current so that the personnel you have enter it are appropriately protected from visible and invisible hazards.

Time is of the essence as your emotions demand you to recover the vehicle as quickly as possible in hopes that your team may save a life, even while the more logical side tells you that with each passing minute that chance is reduced. Your team enters the water exactly where you were told the vehicle would be and after what feels like an eternity, determines there is no vehicle present. As the adrenaline subsides you are trying to sort out the facts, are you in the wrong location, who reported the call, are the divers missing underwater clues to the vehicle’s location?

And then you are reminded of something someone said when you arrived at the scene, there is a witness standing on the bank. Your attention turns and now you are focused on this person, someone who may hold the answers which you desperately seek. You speak to him and determine that he is the owner of the vehicle and yes, it went into the water and is now submerged but the location of it is not where you were told or are searching and that no one was in the vehicle when it entered the water. The reported trapped child was actually his daughter’s baby doll which had been left in the car. As relief comes over you, you realize your focus can now change to a vehicle recovery instead of a potential rescue.

In the aftermath of this call you begin to evaluate your team’s actions and try to seek ways to improve your response. As an ERDI Dive Team Supervisor, you realize a possible improvement step would be to interview all potential witnesses at each scene prior to allowing any divers to enter the water. While you have many other additional responsibilities to complete at a dive site, the realization occurs that you are in the most appropriate position to complete this task.

Being tasked with identifying and speaking to (interviewing) anyone who may have specific knowledge to what has occurred and what you are searching for may be a difficult, daunting and time consuming task. Frequently, in your role as Dive Team Supervisor, there are other issues that you are addressing concurrently while interviewing witnesses and bystanders that compete for your attention. Your experience as a diver is beneficial to you as it allows you to understand and comprehend how to apply the knowledge learned from your interviews to the dive environment, but it is not a necessity.

In this role you are essentially responsible for gathering as much intelligence from the scene as possible. This may include precipitating events leading to the submersion. You should be the only team member tasked with gathering information for the team as it can create confusion and misinformation if more than one person is assigned this task. The goal should be to compile a comprehensive, accurate and objective summation as expeditiously as possible. The fundamental questions of who, what, when, where, and how should be answered if possible. A paramount task in this assignment is the understanding that each witness interviewed is likely to provide a different response to each of these questions. This does not automatically indicate that the witness is being deceptive but may be a result of each individual’s perception of the event being different.

It is your duty to consolidate these in a manner which provides some consistency when passing the information along to the Dive Safety Officer. The Dive Safety Officer should be briefed on any relevant information which may affect the safety of the divers or the security of the scene. It is also imperative your original notes taken from witness and/or bystander interviews be maintained in their initial state, unchanged by anyone present at the scene as these notes may become part of the evidentiary chain of custody.

Your dedicating the time to gather relevant information to be analyzed and evaluated for usefulness allows other team members to focus on completing their assigned tasks without the additional burden of questioning the details or trying to assimilate information from multiple witnesses. It additionally provides witnesses or bystanders with a known person to contact directly in the event they remember or recall information which may be vital to the recovery effort.

Dive Team Supervisors should be articulate, able to multitask effectively and have the authority to make decisions based on the information received for the agency in which they represent. Persons in this role are not required to have completed interview and interrogation training as their mission is more one of fact gathering. However, they should be cognizant that an active public safety dive site is not the time to transition an interview into an interrogation.

In the hectic time surrounding the arrival at the scene, a concerted effort should be made to locate and interview witnesses prior to any dives commencing if the situation allows. Often times this component may not be viewed by some as necessary to a dive team’s operation however it is vitally important. The ability to effectively and efficiently obtain information from witnesses and bystanders prior to divers submerging is an invaluable skill which when applied to a public safety dive team will lessen the risk to all those involved.

– Tanya Chapman – Training Manager – North Carolina Justice Academy
– Instructor – Air Hogs Scuba, Garner, NC


How OSHA Standards Apply to Public Safety Diving Teams

“Hey Chief! OSHA Inspector is here, he’s in your office…”

by Darrell Adams:
erdi ps diverMany dive teams get hung up on trying to figure out if the “Commercial Dive Standard” applies to them and in the meantime forget that OSHA standards and guidelines encompass a variety of other workplace safety issues. In the great debate of whether or not OSHA has jurisdiction, or a standard applies, depends on several variables. First, do you even operate in an area that is subject to OSHA compliance? Outside the USA and its territories this conversation may be moot but that doesn’t mean that these standards do not have merit, can improve workplace safety, and reduce risk to employees if an organization implements them. Second, is there an employee and employer relationship where the employer is obligated to ensure the safety of its employees? This question can be answered by determining if there exists a relationship based upon monetary compensation and/or the act of providing insurance to said person(s). The “Safety and Health Standards: Occupational Safety and Health” website may be of help in developing a basic understanding of OSHA’s purpose and the employer’s responsibilities. Another place an employer should reference is the “Compliance Assistance Quick Start” webpage that provides general information to the basic housekeeping regulations he or she may be subject to. Third, is there an “exemption” that may apply to the standard that allows an organization to opt out of compliance with a standard or regulation due to a certain set of circumstances or provisions that are met?

These questions lead us to the great debate that has existed for years in Public Safety Diving (PSD), “Do we have to comply with OSHA regulations?” The answer is: “Yes and no”.

There are four major groupings of OSHA regulations. They are: General Industry, Construction, Maritime, and Agriculture. Within each of these regulations there exist many sub-regulations that may have application to an organization. An organization really needs to do its own research into each of these areas to determine if they are applicable to them. The regulation section that is most famously referenced in the PSD arena is: “The commercial diving operations standard does not apply to diving operations under the following conditions….. 29 CFR 1910.401(a)(2)(ii). Diving solely for search, rescue, or related public-safety purposes by or under the control of a government agency.”

The polarization and scrutiny that this one statement has caused within the PSD community has resulted in marriage breakups, bar fights, and social media battles of wit. But seriously, so many divers in our PSD community get caught up in the determination of application that we fail to see the true purpose of this standard in a commercial setting and its merit in the public safety diving arena. I would challenge everyone to look at the ocean instead of the waves. Take this regulation, read it, dissect it, and relate it to the scope and application for your own organization. Then ask yourself can this help us be a safer organization and what is the cost of doing so versus the cost of not doing so? You may find there are parts of this regulation you already meet, some you could implement fairly easily, and others that will take time and or money, but it can provide you with a framework and a set of goals for which you can strive. There may be parts of this regulation your organization finds are not applicable due to the diving environments and conditions you operate in. In other cases you may find there are environments you should not operate in until you can provide a better risk assessment and compliance. Below are some, but not all, of the other relevant OSHA regulations that should be considered. Take time and see if they apply to your organization.

1910.101 Compressed gases
1910.133 Eye and face protection
1910.134 Respiratory protection
1910.135 Head protection
1910.136 Foot protection
1910.138 Hand protection
1910.146 Permit-required confined spaces
1910.147 The control of hazardous energy (lockout/tagout)
1910.151 Medical services and first aid
1910.183 Helicopters
1910.184 Slings
1910.242 Hand and portable powered tools and equipment, general
1910.1020 Exposure & medical records access
1910.1030 Blood-borne pathogens
1910.1200 Hazard communication
1926.106 Working over or near water

One of the complaints about OSHA is that the regulations at times are outdated and do not keep up with technology and advancements within our industry. OSHA enacted a Standards Improvement Project (SIP)-III in 2010 which is “a proposed rule to revise and remove requirements within several OSHA standards that are outdated, duplicative or inconsistent. This rulemaking will help keep OSHA standards up-to-date and will help employers better understand their regulatory obligations.” As professionals in the industry we can make recommendations and suggest changes. The websites for this are: or

OSHA regulations are designed to keep employees safe and are not a bad idea to consider if they can help you keep employees safe and can keep costs down by preventing injuries. OSHA will also reference the CDC NIOSH recommendations when conducting investigations. These recommendations can be found by searching diver fatality reports on the CDC: NIOSH website. These reports can provide invaluable insight into why public safety diver fatalities happen and how we can prevent or reduce the risk of similar events from happening in the future. Another great article on this subject is “OSHA Standards and PSD Teams” by Michael Glenn.

Darrell Adams
SDI/TDI/ERDI Instructor Trainer with Air Hogs Scuba in Garner, NC, Captain with the Harnett County Underwater Search & Recovery Dive Team and technical rescue instructor for the NC Fire and Rescue Commission.


4 Tips for Getting Tethered Safely

by Ron Dorneker and Sean Harrison:
tethered diver

Interview with Deputy District Chief for Chicago Fire Department, Ron Dorneker

ERDI – Chief Dorneker, first off, thank you for taking the time to sit down with Emergency Response Diving International (ERDI) and discuss what we think is a very important topic. There are varying opinions on whether divers should be tethered or not but for the purposes of this article we are going to discuss it from the point of view that all divers are tethered.

Before we get into the time tested tips you have to offer, let’s give the readers a little background on you, and your team, so they have a better understanding of the size and typical number of responses and environments your team dives in.

Chief Dorneker – I have been in charge of the Chicago Fire Department Marine & Dive Operations since 2001. There are approximately 140 Chicago Fire Department personnel currently working as Public Safety Divers. This includes divers assigned on our Helicopters, FastBoat 688, SCUBA Team 687 and Squad Companies 1, 2, 5 and 7. These divers act as first responders to immediate life threats due to drowning anywhere within the open waters of Lake Michigan, Lake Calumet, Wolf Lake, the Chicago River, the Calumet River, the Shipping and Sanitary Canal as well as lagoons and ponds around the city. A mutual aid is also given to surrounding inland lakes and the Lake Michigan waterfront of surrounding suburbs. Diving conditions can include black water, polluted waters, extreme cold and ice conditions, and during severe weather and night time operations.

Last year the Chicago Fire Department responded to 249 water rescue incidents. Those incidents included drowning, persons having general trouble in the water, persons missing in the water, jumpers from bridges, persons in or on the ice, vehicles in the water, boat sinkings, boat fires, stranded boat, boat accidents, animals in the water or in/on the ice, victim recovery operations, roadway floods, and rescues of people from their homes during residential flooding.

Also last year, the Chicago Fire Department Divers logged over 3200 hours of training for those types of incidents.

Tip 1

ERDI – Thank you for that very insightful behind the scenes view of your team. Very impressive! Let’s get to the topic at hand and see if we can break this down into critical components. Having watched you work with your team over the years, I know you keep a pretty close eye on things and constantly analyze if operations are working or how they could work better. Staying on the cutting edge of safety. What is the first thing your teams does when it comes to tethering?

Chief Dorneker – Our divers wear a chest harness over their dry suits and under the BCD. The attachment point on the harness is a D-Ring located at the center of the chest. We fasten a carabineer to our tether lines and attach that to the D-Ring. Once the diver is connected to that tether line, the tender must hold that line in his hand until the diver is dressed down and the line is disconnected.

Tip 2

ERDI – What kind of checks or inspections does your team perform?

Chief Dorneker – Tether lines are inspected each day by the oncoming team of divers as part of their daily inventory. The team also inspects the lines before each dive, and again after the dive when being put back in service. This inspection is overseen by the Dive Supervisor.

Harnesses are inspected by the individual diver each day before being put in service. The harness is checked again during a tender check of the diver before we begin the dive. This inspection is also overseen by the Dive Supervisor.

Tip 3

ERDI – What is the reasoning behind tethering your divers?

Chief Dorneker – We tether our divers for two reasons, safety and search effectiveness.

As far as safety goes, Chicago Fire Department divers are always tethered and use full face mask communications during all dive operations. This allows the team to know the exact location of the diver in the water. During any diver distress, our contingency training and plan uses that tether line as a means to descend directly to the distressed diver. Descending on that line saves time. Time is always our enemy when it comes to water rescue operations.

With regard to effectiveness, after identifying the last seen point and determining the area to search, we direct our diver to search an exact area. We call that area “the box.” The tender uses landmarks to keep the diver in the box and conduct a thorough search. We know how long each leg of the search will be, and how many legs of the search the diver will swim to search the entire box. Having the diver on a tether and being tender-directed allows us to factor in visibility to maximize our efforts. We know from the diver what the visibility is during the search. This allows the tender to modify the patterns so the diver does not have to swim to the edge of the box. The tender can stop the diver short on each leg of the box based on visibility. This saves time, has the diver swimming less distance and results in a quicker search of the area.

Tip 4

ERDI – Any other thoughts on tethered divers?

Chief Dorneker – Solo divers being tendered, directed during search and rescue operations, require training on both the part of the diver and tender. It is not easy for someone not used to diving with tether lines to master that skill. It is also not easy to communicate simple thoughts from a tender to a diver. Standardized patterns and standardized communications helped our team achieve success with solo divers being tendered, directed to locate victims and also helped keep our team safer.


Reflections of a Public Safety Diver

by Darrell Adams:
PS DiverThere are many moments in a public safety servant’s job that leave lasting imprints which will mold one’s own mindset by which they govern all future personal actions. These reflections, whether good, bad, or indifferent, make up critical waypoints in a person’s personal journey throughout his or her career that lead to the choices made or not made when called upon in the service of public safety.

“If we were logical, the future would be bleak indeed. But we are more than logical. We are human beings, and we have faith, and we have hope and we can work.” – Jacques Cousteau

So throughout our careers, if we are not making a positive difference in the lives we affect like those of co-workers, peers, patients, and victims, then we have failed in the calling of service. There are many times while in the performance of our job we are faced with interactions that can truly make a difference in the lives of those for whom we have been called upon to provide assistance, and to those with whom we serve. A personal challenge everyone should take upon themselves is that we start every day and service call with the notion that we can help those in need, and ensure that our jobs do make a difference.

When reflecting upon the calls over my career with which I have been fortunate to have been involved, I realize I have many times seen desperation in the eyes of loved ones who are looking for some answers to questions or seeking closure regarding something tragic or unimaginable. I remember a particular incident that happened on Father’s Day when a family was out boating on a lake and the dad had fallen off the boat and failed to surface. The grieving family made a religious request that many of us were not familiar with after they had sought counsel. These few moments that this family needed that ceased our operation mid-stream, I later found out ultimately meant the most to them as to the overall comfort for this family when dealing with the loss of a husband and father. This family’s clergy also offered religious insight with regard to assisting with locating this victim. We advised the family that we would use this information in our recovery attempt. Having the willingness to be understanding of cultures different from one’s own can only help the healing process of those who are grieving. Taking the time to listen can make the biggest difference.

This does lead me to another topic associated with the interactions of family and friends during an operational period. Many times at the scene of recoveries it can be seen where family and friends want to help in any capacity possible because sitting and doing nothing does not seem logical for them. Friends and families of victims may also not understand the method to our madness when it comes to search pathology. Taking a few extra minutes to explain to the family what a search might entail may help reduce tensions and emotional reactions against the response personnel. Another response that comes to mind was when a young child was playing near a swollen creek that was about ten feet above flood stage. The child fell into the water. This was a call that lasted seven days and required the response of many teams over those days. Some of the family members grew impatient due to not understanding what was involved in a search and recovery operation in a moving water environment. Working with extended family and their clergy to help clear tensions, the divers were able to finally bring closure for them. Later, these families came back and offered their thanks for helping in a time of need.

After the recovery of a loved one, the healing process takes a new path and can be difficult to navigate for some. Seeking assistance from others who can relate can move a person along a better path of coping with loss. An excellent resource to provide for grieving family members is the “Drowning Support Network” that was founded by Nancy Rigg after the loss of her fiancé. This group has a closed Facebook page and Yahoo group that family members of drowning victims can join and seek assistance from peers.

As public safety divers we have the opportunity to make a positive impact in the lives of those we are called to serve. They may not understand what it takes to do our job and the amount of time, commitment, and expense entailed. However, taking those few minutes to let them know you care and what you are trying to do to help them, does make a difference to them.

Darrell Adams
SDI/TDI/ERDI Instructor Trainer with Air Hogs Scuba in Garner, NC, Captain with the Harnett County Underwater Search & Recovery Dive Team and Technical Rescue Instructor for the NC Fire and Rescue Commission


3 Essential In-Water Communication Skills for Public Safety Divers

by Dr. Thomas Powell:
PSD diver
Imagine you are 15 feet underwater in a zero visibility environment, alone, and searching through the unknown for the remains of another human being. You do not know the layout of the underwater environment, nor are you aware of any potential obstructions or tangle hazards. These are the moments that public safety divers deal with around the world every day. The public safety realm is one in which safety is critical and redundancy is the norm. Moments like the one described above show why equipment and action redundancies are designed, planned, and implemented.

Communication is often the thing that can calm the nerves of a public safety diver. A new diver settling into black water for the first time may be filled with anxiety and breathe so hard he or she burns through air too fast to perform a legitimate search pattern. Tenders often discover that one of their primary roles is to calm the diver on the end of their tethers. A friendly and supportive voice can help center a diver and bring him or her back to reality and back on track. When voice communications fail, the ability to help a diver remain calm may falter. For this reason, both divers and tenders need to understand and be able to perform communication activities using various redundant methods.

Voice Communication
Voice communication is the most simple and modern version of diver communication. Essentially, a diver can use a voice activated or push-to-talk system to speak openly to a base station, receiver, or tender. Surface personnel can also communicate back to the diver. In the case of wireless communications, or multiple divers with hardwired communications fed into the same surface system, the divers may also have the ability to communicate between one another. Voice communication systems allow divers to discuss plans, actions, and events as they arise. Surface personnel can be apprised of what is taking place underwater and provide direction as needed using real-time explanations. The problem with voice communication systems is that sometimes electronic systems fail underwater.

Line Signals
Line signals are another form of communication. They are a signaling method used among different types of public safety organizations to signal actions and well-being. Because so many organizations use line signals, they become an action set that can easily be transitioned into a diving environment. Line pulls are based upon the idea that the tether between a tender and diver remains taut. A certain sequence of pulls from any direction is pre-planned to have a certain meaning. Using these pull sequences, the diver and tender can remain in communication when voice-based systems fail. To remain competent in the use of line signals, they must be practiced by divers and tenders. Divers must work search patterns and practice keeping the tether line tight. Simultaneously, the diver must practice relying on the tender for directional cues. Without directional cues, the diver may perform an improper search pattern if he or she does not have the ability to see. If these actions are not practiced, both divers and tenders will forget line-pull sequences and perform poorly during critical situations.

The availability of voice communication systems often make dive teams lazy in the sense that they rely too much on the electronic systems and do not practice redundant communication methods. The other factor that must be remembered is that divers are rarely tethered together barring situations such as ice dives. This reality suggests that line pull signals are not often available for divers to communicate between one-another unless a diver-to-diver tether is put into place. For this reason, hand signals are essential as a redundant form of underwater communication between divers.

Hand Signals
Finally, hand signals are one of the most basic forms of underwater communication. All divers know them and practice them throughout all forms of scuba training. Hand signals work between divers underwater when all other forms of communication fail. The catch is that divers choosing to dive together must work to understand what certain hand signals mean. Different divers may choose to use imperial or metric gauges (different measurements to signal), or to express information using different methods. To prevent confusion or misunderstanding, divers must verbally and visually walk through hand signals on the surface before entering the water.

Public safety divers must also practice tactile hand signals. In the public safety world, black or brown water environments are common. Environments such as these often eliminate visibility and the potential use of common diver-to-diver hand signals. Tactile hand signals are based on the idea of one diver touching another diver in a certain manner that has pre-determined meaning. When divers cannot see, tactile hand signals allow those divers to communicate through basic touch. Again, these types of hand signals must be practiced to ensure understanding and basic use prior to diving.

Communication is critical for public safety divers. Divers must know they are supported by a surface team that understands the situation, and surface personnel must know how best to protect and support divers under the water. When one method of communication fails, the failure may be based on an incident endangering a diver. For this reason, redundancies are essential when communication is involved. Line and hand signals allow a diver to communicate with other divers or a tender when electronic communication systems fail. To remain safe and competent, divers must practice and train in the use of redundant communication methods. Practice will ensure muscle memory and clear mental recall of communication methods. Safety is critical in the public safety world, and with practice and training public safety dive teams can set themselves up for success.

– Dr. Thomas Powell
Owner/Instructor Trainer – Air Hogs Scuba, Garner, NC


Hydrology of Currents: What Public Safety Divers Should Know

by Darrell Adams:
psd diver in current
Some of the most challenging environments a public safety diver (PSD) can encounter are ones that deal with the forces of Mother Nature. At times she can be so unpredictable. However, with proper training, pre-planning, hazard/risk assessment, and incident evaluations, PSDs may be able to alter the tides of the unknown to establish a strategically planned operation. This operation would create a mitigation plan for problematic factors that promotes a greater margin for success and safety. In the PSD arena we all know that there are many factores that cause unique problems, but one of the most challenging and dangerous ones are those that deal with currents. Whether it involves the rivers of the Appalachian Mountains, canals of the metropolis areas in California, or the surfs of the New England coast line, teams responding to these environments need to understand the risk related to operations pertaining to “current hydrology.”

When evaluating PSD operational environments with regard to currents, the determination of the “mode of the response” should be part of the primary assessment. Will the team’s efforts be channeled into a rescue mode or that of a recovery? We can all agree that when operating in recovery mode, the time of recovery may not be as crucial as it would be in a rescue. As mentioned before, there are many different environments in which PSDs are likely to encounter currents: rivers and streams, canals, floods waters, surf, open oceans, and river deltas just to name a few. Each of these different environments possesses unique current hydrology hazards that need to be recognized and for which mitigation efforts must be implemented. In-depth understanding of any such hazards found within a team’s jurisdiction requires the team to spend a considerable amount of time educating members and getting plenty of water time to develop the skill sets needed to operate more efficiently while fostering reduced risks through effective hazard mitigation efforts.

Moving water is a very powerful force. There are several things that go into factoring the power of moving water like: speed, volume, bottom contours/gradient, tides, and winds. The current hydrology characteristics of rivers, streams, and canals deal with the volume of the waters flowing, the speed, and the bottom/side topography. The speed of the current when increased has a direct correlation to its force. For example, when the speed of a moving body of water is doubled, the force of that water imposed on the diver or object in the water is quadrupled. So waters moving at 2.5 knots can impose about 34 pounds of force on a diver, but when the water speed increases to 5 knots it can impose approximately 136 pounds of force on the same diver. The speed of moving waters in a river, stream, canal, or flood scenario are in direct relation to the size of the passages the water is flowing through and the effects of gravity based on the gradient at which the water is moving. The current speed of a section of moving water can be estimated by timing an objects passage between two points and referencing a chart which may be expressed in feet per second (fps) or meters per second (mps). With the speed now factored, consider the volume of water that is moving. This can be sometimes calculated or derived from monitored sources like USGS for which cell phone applications have been developed. Water volume is typically expressed in cubic feet/second (cfs) or cubic meter/second (cms). So let us imagine we have a stream bed that is 20 feet wide and 15 feet in depth, and water is flowing at 5 fps. That would come up to 1500 cft. of water moving by every second. Since a cft of fresh waters weighs 62.4 lbs., let us imagine about 1500 basketballs flowing by every second that weigh 62.4 lbs. What kind of power that would be?

This force of water can cause complications in regard to operations in certain environments. The act of swimming, walking, or diving into a current can be very dangerous. There are mainly three options when determining the dive platform: shore based, boat based, or bottom based. In a river-type situation, shore based searches in currents may result in a diver’s movement being unpredictable and search pattern management may become unreliable due to the speed a diver or swimmer is moving with the current. The task loading of swimming against a current may also result in a loss of focus and result in increased air consumption rates. Tender operations may become problematic because of issues with line management and the effectiveness in location accuracy as a result of line deflection. Therefore, operations on a boat anchored by a static highline or anchor, and bottom based searches tend to result in a more effective operation. These platforms tend to address some of the previously mentioned issues and establish something more manageable. One issue that may arise in these operations is the planning of a tethered diver. Variables relating to this would include the speed of the water’s movement, the length of tethered line, and the weight of the diver. Line length and weight may be adjusted to achieve effective search positioning. PSDs have to be cautious in over-weighting along with the streamlining of one’s gear. Another problem is object drift. Depending on force, bottom composition/contour and debris, the item(s) for which a diver is searching may move or be covered up, making item discovery more tedious.

Now if we throw in the other hazards associated with these environments like hydraulics caused by objects in the pathway of water flow that may be permanent. These objects may include but are not limited to rocks and boulders, low head dams, ditches on flooded roadways where water is moving across, and/or movable objects like vehicles in a river. Other hazards can be loads (objects in motion in the water column), strainers and sweepers (things in which divers or objects can become entrapped that are on the surface and below the surface of the water), pollution, and entrapments/entanglements. With so much to consider in regard to the hazard and risk assessment for operations in these environments, one can understand the need for proper equipment selection and training in many different technical rescue disciplines. It is highly encouraged that teams operating in moving waters like rivers and streams be trained in technical rope rescue applications, surface water operations for moving water, and small boat operations before commencing operations in these types of moving water environments. ERDI has training programs that can assist teams with achieving these goals.

PSD operations in ocean environments offer their own unique problems as well. Teams that are conducting rescues and recoveries in surf/open ocean and river delta environments may be dealing with a variety of current hydrology issues that if not considered, may complicate or jeopardize the safety of team members. Some of the ocean forces to be addressed are tidal currents, longshore currents, rip currents, undertows, surges, and waves. The problems posed by these forces can be lessened by pre-planning dive operations with a team’s jurisdictional support resources and an effective incident size-up. Also, by training in these environments teams will have a better clarity in trying to determine the “point last seen” (PLS) of victims and/or objects being recovered. These types of environments are always changing and can be problematic for operations that span a timeline across these changes. For example, the bottom topography in a surf zone is always changing due to the waves, surges, and tides and that may tend to cover objects on the bottom. Situations such as this may make it more difficult to locate or even move the object(s) from their original PLS. Some of the same issues with searching in river type incidents also may apply to ocean-based scenarios like pattern management, air consumption, weighting, streamlining of gear, and equipment selection.

Public safety divers have many factors with which they must contend in regard to the performance of standard operational activities. The number one job for any PSD is to get home at the end of the day. For this reason, risk assessment and hazard mitigation do take center stage in the operational game plan. With regard to “current hydrology,” individuals need to remember that there are no walls in the ocean to hold on to when you get tired, and you cannot call a time out when problems arise. Bret Gilliam stated once, “He who prepares and anticipates his adversary, whether narcosis or the great white shark, will handle the situation well. And likewise, he who hesitates… is lunch!” Therefore, as PSDs, the key to success involves training, to train again, and to train some more. This cannot be further from the truth when dealing with currents. ERDI programs offer building blocks for success for teams dealing with moving waters as well as other hazards.

– Darrell Adams
SDI/TDI/ERDI Instructor Trainer with Air Hogs Scuba in Garner, NC, Captain with the Harnett County Underwater Search & Recovery Dive Team and Technical Rescue Instructor for NC Fire and Rescue Commission


ERDI Public Safety Diving Health Project

by Sean Harrison:
ERDI Divers
ERDI was invited, along with several other industry professionals, to attend a workshop that focused on the health and well being of public safety divers and their support teams. The workshop was hosted by UC San Diego Health Sciences, Center of Excellence in Diving; and sponsored by: Scripps Institution of Oceanography, OxyHeal Health Group, Divers Alert Network (DAN), ScubaPro, and Diving Unlimited International (DUI). Just by looking over the host and the list of sponsors, you can tell that this was not your average workshop.

The stated goal was, “To create knowledge and competencies in recreational, scientific, commercial, military and public safety through diving research, education, and ocean conservation.” One might wonder how do all these very different sectors of diving relate? Well, there is one common denominator… the water. From the brand new open water diver to the best trained combat diver, every one of us is subjected to the same environmental factors, we may have different reasons for being in that environment but nevertheless, we are being exposed to the same things.

ERDI began its quest to educate the public safety diver of the hazards, concerns, potential exposures and mitigation strategies to protect against these contaminates in 2010 by publishing the Contaminated Water Diving Operations manual. ERDI welcomed the invitation to contribute to the health of the divers and to the environment.

A lot of topics and ground were covered during this workshop. There were some reoccurring topics that need to be addressed and some new ones. With the wide range of experience that was in the room, there was a flurry of conversation and some very sensitive topics exposed. The end goal was always the safety and well being of the divers, no matter what the reason was the diver was in the water.

Since this was the first meeting, everyone involved was sent home with one goal… go on a fact-finding mission, and learn what the divers in our respective communities are feeling. For the public safety diver this could mean some self reflection – how did I feel before and after that dive, how did I feel two days after that dive?

Every new venture takes a while to mature and public safety diving is no different. While divers have been going in the water for many years to recover objects and bodies, public safety diving is really only now coming to the forefront and gaining enough attention as a service that is desperately needed by the community it serves. The end result is: with enough awareness and research data, teams that need funding to obtain necessary training and equipment, will have the documentation they need to support their requests. For the teams that are already well funded, they will benefit by continuing to do their job with the most current equipment and training and… maybe even an “I told you so.”

ERDI will continue to assist with this important mission in any way we can. We will also keep you up-to-date on any progress that is made. For more information or to see how you can be involved visit the UC San Diego Health Sciences website or keep checking back to ERDI News for updates.


4 Tips to Help You Prepare to Testify in Court

by Dr. Thomas Powell:
courtroom gavelWithin the public safety community the court room is a place to which individuals may be called at any time. Legal proceedings surrounding injuries, recoveries, operations, and activities may require individuals, groups, or even whole teams to bring insight before jurors or a judge. For this reason, public safety dive teams must be prepared to explain their actions and findings involving any operational activity. Though being called to court is not a common occurrence for public safety divers, training must be put into place to prepare for what MAY happen. A lack of preparation could bring harm to the stability of a dive team or even allow a law-breaking individual to go free because of a lack of information, evidence, or observable competency from the dive team. A dive team member who performs perfectly underwater, but who cannot face an attorney may present what appears to be incompetence to a judging group of jurors.

Emergency Response Diving International (ERDI) has developed a course program designed to help dive team members be mentally prepared to face the courtroom. This program, Testifying in Court, discusses topics from proper wear and appearance for courtroom proceedings to preparation prior to court. Being prepared is the most efficient manner in which a diver can comfortably face questions from attorneys and provide truthful and quality data as needed.

Four tips that can help any public safety diver prepare for court:

Review the subpoena

A subpoena is a legal document issued by a governmental body (most often the court) to an individual or group requiring that person or body to present information. If that person or body does not follow through with the presentation of evidence or information, the person or group will be penalized. If a dive team or dive team member is presented with a subpoena, the document should be reviewed for information. A subpoena will often provide information regarding the evidence or testimony desired by the court system as well as the names and actions related to that evidence or testimony. The date, type of court, time, and location of the required presentation will also be listed along with the attorney who issued the subpoena through the court system.

A subpoena must be reviewed to make sure that a dive team or team member understands why they are being called to appear, what items must be taken to present to the court, and when and where the person or group must be available to sit before the court. Understanding this information will also help establish a timeframe for preparation and presentation practice.

Review the dive reports

Once a subpoena has been reviewed, all information regarding the associated dive operation must be pulled and reviewed and by all available parties who partook in the operation. Team members must work together to develop a comprehensive knowledge and understanding of what actions were performed, what items were found, and how that information was documented. This may also involve photographs, sketches, or other forms of documentation that must be compiled and copied for the court.

A diver should never enter the courtroom without understanding what took place and his or her actions in a clear fashion. For this reason, team members should rely on each other and documented information to ensure that a clear memory is recalled. A lack of memory regarding an old operation will not be viewed as acceptable or competent within a courtroom setting.

Meet with the attorney or solicitor

Next, a team must take the time to meet with the attorney or solicitor who generated the subpoena. A meeting of this type will help establish what information must be presented and in what manner. Essentially, the person or persons presenting information will be better able to prepare and present relevant information and avoid unforeseen questioning. This meeting will also give both parties the opportunity to plan out pertinent questions and responses associated with case-based information.

Know where to go

Finally, the diver or team members required to appear before the court must know where to go and when. If an individual fails to appear in court in response to a subpoena, that person can be held in contempt of court and face legal consequences. Similarly, the individual being asked to testify may be viewed as incompetent, and therefore critical case-related data may be eliminated from court proceedings. A situation such as this may even cause a case to be dropped and a potentially guilty defendant to go free.

When the court system calls upon a diver, that diver must be prepared to present knowledgeable and quality data in a competent fashion. To accomplish this goal, dive teams must be prepared for the potential need to present information in court through the development of both education and mission records. ERDI has developed an educational program to help any team achieve this objective. Through competent action and the ability to record and recall information, teams can both justify actions and verify operational credibility.

– Dr. Thomas Powell
Owner/Instructor Trainer – Air Hogs Scuba, Garner, NC


Inspecting Cylinders – Beyond the Hydro

by Don Kinney:
visual inspectionThe primary rule affecting the inspection of high pressure cylinders in the United States is the U.S. Code of Federal Regulations (CFR) 180.205. This section refers to the hydrostatic requalification of cylinders, but also mentions that during this requalification, a visual inspection must be performed. The hydrostatic requalification may vary amongst high pressure cylinders, but a common time frame is every five years. This infers that a cylinder gets a visual inspection every five years, even though cylinders may be exposed to safety concerns countless times within a five year cycle.

Scuba diving organizations, being aware of these hazards, encourage annual visual inspections of cylinders. The National Fire Protection Association (NFPA) 1852 ( requires an inspection of the cylinder at the beginning of each duty period. The Occupational and Safety Health Administration (OSHA) requires that each employer ensures that gas cylinders are safe, which can be determined by a visual inspection (1910.101(a)). None of these rules or regulations explain what to look for during these visual inspections. How can a person know what conditions are considered a safety risk?

A proper high pressure cylinder visual inspection course will show a user/inspector what conditions are acceptable and what conditions could be dangerous. The course also helps guide the user/inspector on what the next steps are to ensure safety. Each type of cylinder has unique characteristics which must be monitored to ensure its structural integrity.

steel cylinderSteel cylinders are common in most industries. They include storage, fire suppression, scuba diving and compressor systems. They are susceptible to moisture from their storage environment and need to be closely monitored for issues of corrosion. These cylinders are also commonly transported from location to location and have specific safety protocols; such as attaching caps during transportation and being properly secured during use.

Composite cylinders are light weight and handle greater pressures than their solid metal counterparts, but that does not mean that they can handle the same type of environment or abuses. Users/inspectors must pay close attention to cuts and gouges, as even a small cut can render the cylinder condemnable. They also respond differently to impact damage, which might not be easy to detect without proper training. These cylinders also are highly susceptible to chemical exposure and a minor incident involving a chemical might condemn a composite cylinder.

abrasionAluminum cylinders are common in the beverage, scuba diving and medical industries. Aluminum is softer than steel, but the walls on the aluminum cylinder are manufactured with a thicker dimension than steel or composite. Even with these thicker walls, aluminum cylinders are prone to cuts and gouges which may render them unsafe . Some aluminum cylinders also require specific testing during a hydrostatic requalification and a closer inspection of the threads before continued use.

Cylinders are exposed to extreme conditions on a regular basis, thus it is recommended that they are inspected more frequently than every five years. Some of these exposures may make a cylinder unsafe long before it is due for it’s next hydrostatic requalification. A cylinder inspection course will train the user/inspector on the unique characteristics of each type of cylinder and how to recognize potential dangers before they become dangerous hazards.

Don Kinney
High Pressure Cylinder Inspecting Instructor

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