Posts

Extend Your Limits With Trimix

In reality, Trimix is a risk management breathing mixture utilized by divers typically seeking to offset the consequences of diving normoxic air or nitrox mixtures at a planned diving depth by replacing much of the nitrogen and some of the oxygen with more benign inert gases like helium.

Buoyancy Compensators: Special Features Needed for HAZMAT Conditions

A lot of times we get focused on the personal protective equipment that keeps the diver encapsulated in hopes that the diver has reduced exposure to the materials they may come in contact with and we tend to forget about the other support ensemble and ancillary equipment that is also exposed to the same environments.

Basic Skills Tech Divers Tend to Get Lazy With

tech skills
When the first “Technical Divers” started to evolve and climb out of the primordial soup of the sport realm, some would argue they were light years ahead of the modern day sport divers of today who desire to make the same journey. Without getting into a great debate on the evolution of diver education, the modern day student does lack something of the days of old. The lacking factor is the relentless requirements of skill set repetition until those skills evolve into muscle memory that develops into a diver’s ability to have “Recognition Prime Decision Making Skill Sets.” “Recognition Prime Decision Making Skill Sets” is simply a model of how people make quick, effective decisions when faced with complex situations. One must ask, what happens to the tech divers who have demonstrated basic skill sets in training where they meet the requirements of certifications but do not seem to be very fluid or competent later in the execution of the same skill sets in future training dives or when needed? One thing we must ponder is, what is the culture within the “Tech Diving Community” when it comes to currency and proficiency of basic tech diving skill sets? English Anthropologist Edward B. Tylor defined culture as “the full range of learned human behavior patterns.” “This may be the most intuitive principle of learning, traceable to ancient Egyptian and Chinese education.” Aristotle once commented that repetition in learning “is frequent repetition that produces a natural tendency” and “the more frequently two things are experienced together, the more likely it will be that the experience or recall of one will stimulate the recall of the other”.

“Our humanity rests upon a series of learned behaviors, woven together into patterns that are infinitely fragile and never directly inherited.” – Margaret Mead

Diving culture is a very powerful influence within our community that is constantly evolving due to technology changes, the better understanding of science when it comes to diving physics and physiology, and the educational/philosophical differences among divers/training agencies. The hard and fast influences of diving peers, traditions, and the trials and tribulations of the pioneers before us are also factors that affect the evolution of learned behavior. So in the diving community we have the cultural traditions of the past, sub-cultures (separated ideology), and the cultural universals (ideologies that everyone accepts as the norm).

“The effects of repetition on a single association of stimulus and response with the effects of practice on the development of skill, which is something quite different. In learning any skill, what must be acquired is not an association or any series of associations, but many thousands of associations that will connect specific movements with specific situations.”

So whether you are “Tech Diver of Old” or a “Newbie Wet Behind Ears,” there are skill sets we all can, need, and do desire to improve/refresh upon or hone into a better mastery of. These actions take repetitive practice. Whether it is learning to deploy an SMB, performing a valve isolation and shut down, or working through managing a diving emergency, there are four stages one must swim through in skill development:

  1. The Novice – Mastering a craft does not happen overnight.
  2. The Apprentice – Realize your personal limitations.
  3. The Journeyman – Where the real work begins. Practice makes perfect.
  4. The Master – Unconsciously competent

“To become a master at any skill, it takes the total effort of your: heart, mind, and soul working together in tandem.” – Maurice Young

The law of 10,000 hours

Author Malcolm Gladwell, in his book Outliers: The Story of Success, states that “you need to have practiced for 10,000 hours, or roughly ten years, to become a genius at something. It means ‘success’ isn’t necessarily genetic, socioeconomic or generational.” So if you find yourself as the “Novice” standing on the shore dreaming of the water, or on a boat sailing down the road to “Mastery,” it can be concluded that it is not always an easy journey to log the 10,000 hours needed for obtaining mastery of a skill set. Similarly, there is another inherent problem that must be discovered and understood. Once you master a skill set it can be a very fragile learned behavior and it requires a lifelong dedication to maintain or one may slip from “Master” to “Journeyman” in an easy fashion. A famous quote by Confucius, says, “I hear and I forget. I see and I remember. I do and I understand.” Research agrees, and shows that we retain in memory “10% of what we read, 20% of what we hear, 30% of what we see, 50% of what we hear and see, 70% of what we say, and 90% of what we say and do.”

So what skill sets do we tend to get lazy on as tech divers? One of the first we have to look at is equipment configuration. All too often we find ourselves getting complacent and dependent upon the diving gear we have grown to love and trust. After all, we have the best BCD that has a dual bladder, tons of “D” rings, and it is very rugged and durable so we can load it up with weights and the biggest steel tanks (so air management is never an issue either). All jokes aside we cannot cookie cut our dive gear due to the individuality of every diver. So on every dive a “Tech Diver” should put in some dry time preparation on the dive gear to make sure the integrity, functionality, and dependability is there. During gear prep it should be determined that the equipment will perform proper when needed. Similarly, the routing and placement of regulators/hoses, cylinders, and the attached accessories should be ergonomically appropriate for yourself and easily accessible for use and deployment.

Second is tech dive planning – pen and paper time are still a must if want to try and keep “Murphy’s Law” at bay. A lot of divers tend to fall farce to believing “I have a dive computer and it will tell me everything I need to know.” Knowing run times, dive & gas management profiles, the objective, and problem contingencies for a dive is still imperative. Complacency can be unforgiving. Another part of planning is gas analysis. As a diver at any level you should know what is in your cylinder because people do make mistakes. Analyze your own gas mixtures so you know!

Third is weighting and buoyancy. These topics are subjects that “Tech Divers” tend to get complacent about. After all we said we have the best BCD and it can handle it right? Remember, “When the crap hits the fan – there are no time outs.” Knowing the buoyancy characteristics of your diving ensemble is imperative because it does have a direct reflection upon you trim and air consumption, which can affect other aspects of the dive. Being able to control your ascent rate and adjusting buoyancy to neutral during deco stops are directly related to proper weighting and is something one can always strive to improve upon. Some other skillsets that tend to become rusty without practice are:

  • Gas switching drills
  • Valve isolation or shut downs
  • SMB deployments
  • Different finning techniques (frog, backwards kick, scissor)
  • Equipment removal and replacement (stage cylinders)
  • Navigation techniques
  • Line reel management (tie offs, line retraction, entanglements)
  • Loss/disoriented – especially in overhead environments
    • Light failure
    • Silt outs
  • Drysuit emergencies (over inflation and flooding)
  • Hand signals used by tech divers
  • Dive rescue/prevention techniques (dive buddy monitoring, management of an unconscious diver)

An honest self-evaluation of yourself should be done, asking how you can become a better tech diver and member of a tech diving team. You should be open to evaluations by your peers because they may see things you do not notice about yourself. Finally, these actions as well as working with a TDI professional are all avenues one can employ in the journey toward the mastery “Tech Diver” skills. So how many hours do you have invested?


Darrell Adams – SDI/TDI/ERDI Instructor Trainer with Air Hogs Scuba in Garner, NC.

References:

Guidelines of the National Fire Protection Association

by Darrell Adams:
NFPA drill
The National Fire Protection Association (NFPA) standards have become the most widely accepted standards for agencies that are responsible for providing technical search and rescue services in the United States. These standards provide a framework to help agencies more effectively manage their operations, reasonably ensure they have competently trained personnel, and limit liability by conforming or adhering to consensus based standards that have been developed by the search and rescue community, product manufacturers, training organizations and other technical rescue professionals. The NFPA standards address many different professional qualifications for the technical rescue disciplines such as water rescue, rope rescue, confined space, vehicle and machinery extrication, and several more. There are NFPA standards that also cover other aspects like the health and safety of response personnel, as well as working equipment and the personal protective ensemble of the response personnel. NFPA standards are reviewed periodically to address the changes within the search and rescue communities’ methodology and to address manufacturer changes and advancements.

There are two standards that address the majority of the aspects of technical rescue with the first being the NFPA 1670 (Standard on Operations and Training for Technical Search and Rescue Incidents 2014 edition) standard that identifies and establishes the level of “functional capability” for organizations who respond to technical search and rescue incidents. The 1670 Standard outlines how to conduct technical rescue operations safely and effectively while minimizing risk to rescuers. The 1670 Standard is intended to help the “Authority Having Jurisdiction” (AHJ) assess technical rescue hazards within a given response area, identify the level of operational capability, and establish guidelines for incident operations and training. Within this standard it addresses thirteen different technical rescue disciplines (Rope, Structural Collapse, Confine Space, Vehicle, Water, Wilderness, Trench, Machinery, Cave, Mine, Helicopter, Tower, and Animal Search and Rescue). An organization can determine the level of operational capability to each of these disciplines as they apply to their agency based on an individual needs assessment. These different levels of operational capability address specific concerns that are associated with the specific environments. Rope rescue however is one of those disciplines that blends and crosses over into the other disciplines and is not limited by environment. Therefore, it should be considered when an agency is developing programs in these other areas. The levels of operational capability for the disciplines in NFPA 1670 are listed as:

The Awareness Level that “represents the minimum capabilities of organizations that provide response in technical search and rescue incidents.”

The Operations Level that “represents the capability of organizations to respond to technical search and rescue incidents and to identify hazards, use equipment and apply limited techniques specific in this standard to support and participate in technical search and rescue incidents.”

The Technician Level that “represents the capability of organizations to respond to technical search and rescue incidents, to identity hazards, use equipment, and apply advanced techniques specified in this standard necessary to coordinate, perform, and supervise technical search and rescue incidents.”

The second standard is NFPA 1006 (Standard for Rescue Technician Professional Qualifications 2013 edition). This standard identifies the minimum job performance requirements (JPRs) for technical response personnel who perform technical rescue operations. This standard does not limit an organization on training but it does establish a “minimum level of competency for a rescuer” within each rescue discipline. It is aimed at the rescuer’s ability to demonstrate skill proficiency. The job performance requirements defined in chapter five “shall be met prior to being qualified as a technical rescuer relative to the discipline specific chapters.” The subject matter addressed in chapter five is: Site Operations, Victim Management, Maintenance, and Ropes/Rigging. The chapter-specific disciplines of NFPA 1006 are: Ropes, Confine Space, Trench, Structure Collapse, Vehicle Rescue, Surface Water, Swiftwater, Dive, Ice, Surf, Wilderness, Mine and Tunnel, Cave and Machinery Rescue. Within each of these disciplines there are two levels of qualifications:

Level I. This level shall apply to individuals who identify hazards, use equipment, and apply limited techniques specified in this standard to perform technical rescue operations.

Level II. This level shall apply to individuals who identify hazards, use equipment, and apply advanced techniques specified in this standard to perform technical rescue operations.

Some of these rescue environments are low frequency events for a lot of technical rescue organizations and are considered high risk events. So one has to remember that this standard again only establishes the “minimum level of competency for a rescuer” therefore, retention of knowledge and developed skill sets are very fragile. These skill sets must be maintained to ensure that a rescuer is able to perform when the need arises. Monthly, periodic and annual currency and proficiency training is a must for agencies providing technical rescue services. With some disciplines there may be OSHA regulations that also require annual training like confine space and trench.

Some other relevant NFPA standards to the technical rescue arena are:
NFPA 1983 (Standard on Life Safety Rope and Equipment for Emergency Services – 2012 Edition)

NFPA 1951 (Standard on protective Ensembles for Technical Rescue Incidents – 2013 Edition)

NFPA 1855 (Standard for Selection, Care and Maintenance of Protective Ensembles for Technical Rescue Incidents – 2013 Edition)

NFPA 1952 (Standard on Surface Water Operations Protective Clothing and Equipment – 2015 Edition)

NFPA 1936 (Standard on Power Rescue Tools – 2015 Edition)

NFPA 1561 (Standard on Emergency Services Incident Management System and Command Safety – 2014 Edition)

NFPA 1410 (Standard on Training for Emergency Scene Operations – 2015 Edition)

NFPA 1401 (Standard for Fire Service Respiratory Protection Training – 2013 Edition)

NFPA 471 (Standard on Recommended practice for Responding to Hazardous Materials Incidents – 2002 Edition)

NFPA 472 (Standard for Competence of Responders to Hazardous Materials/Weapons of Mass Destruction Incidents – 2013 Edition)

NFPA 473 (Standard for Competencies for EMS Personnel Responding to Hazardous Materials/Weapons of Mass Destruction Incidents – 2013 Edition)

NFPA 1500 (Standard on Fire Department Occupational Safety and Health Program – 2012 Edition)

NFPA 1521 (Standard for Fire Department Safety Officer Professional Qualifications – 2015 Edition)

NFPA 1583 (Standard on Health-Related Fitness Programs for Fire Department Members – 2015 Edition)

NFPA 1584 (Standard on the Rehabilitation Process for Members during Emergency Operations and Training Exercises – 2015 Edition)

NFPA Standards on the horizon:
NFPA 1952 (Standard on Protective Ensembles for Contaminated Water Diving – Proposed future date 2016)

NFPA 1986 (Standard on Respiratory Protection Equipment for Technical and Tactical Operations – Proposed future date 2017)

The NFPA Standards exist to provide an organization with a foundational framework for agency operation and incident management as well as training guidelines. While these standards are not regulatory, they have been widely accepted among those in the technical rescue arena as a consensus-based standard. They should be considered when an agency is looking into organization development and training programs. One really should obtain copies of the standards that are and will be relevant to them, and really dive into them to grasp a better understanding of them. The training programs of ERDI have been, and will continue to be, researched to make sure they achieve adherence to the relevant NFPA standards as they apply to agency programs. “There are no walls in the ocean to hold onto, no time-outs can be called, and re-dos are not granted when things are not going as planned.” Proper planning prior to an emergency is paramount. So grab some coffee and sit back with the Lil’ red books of NFPA.


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

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. http://www.dol.gov/elaws/elg/osha.htm. 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. https://www.osha.gov/dcsp/compliance_assistance/quickstarts/general_industry/gi_step1.html. 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.” https://www.osha.gov/OshDoc/Directive_pdf/CPL_02-00-151.pdf.

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: http://www.regulations.gov/ or https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=NEWS_RELEASES&p_id=17928

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. http://www.cdc.gov/niosh/. 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. https://www.tdisdi.com/osha-standards-and-psd-teams-are-we-really-exempt/.


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.

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

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