A child follows his dog onto a frozen lake and falls through into the icy water. A car plunges off a bridge into a murky river. A crime is committed and the evidence lies at the bottom of a bay. These are the kinds of scenarios that call for a dive team. There has been a great increase in awareness of the need to respond effectively to water emergencies and underwater investigations.
A one-day public safety agencies’ seminar was hosted by the Diving Equipment Manufacturers Association (DEMA)
during its annual meeting. DEMA annual meetings alternate between Las Vegas and Orlando. Among DEMA exhibitors and presenters are representatives of many diving organizations that focus on public safety diving. Among these are Dive Rescue International
and the International Association of Dive Rescue Specialists
The Las Vegas conference of 2010 was presented by Andrea Zaferes and Walt “Butch” Hendrick of Lifeguard Systems
. Zaferes and Hendrick are specialists in water operations training and equipment, and their seminar focused on safe diving during rescue, recovery and investigation.
“There are tricks of the trade” to be safer, Zaferes said. Every dive team needs to know all the procedures and techniques that keep the team safe because the goal is to be sure those team members “go home every single time.” Understandably, there is much emphasis on the victim or evidence in the water, but there must also be considerations for diver safety. As an example, Zaferes posed the scenario of a rescue under an icy lake. “An icy lake means thin ice. And no ice is safe ice,” she said. “If there’s been a 9-1-1 call, then the ice is too thin.”
Whether it is ice, murky water, an overhead environment, fast current, an underwater cave or polluted water, there needs to be “real life training for real life operations,” she emphasized. Difficulties, potential problems and safety considerations must be addressed in training, and also on every dive.
Hendrick said the question must always be, “How do we keep people alive on the job?” That means looking at the operation in a realistic format, not as “normal” or “sport” diving. For example, going back to that rescue under an icy lake, it is relatively easier to find someone because the last known location is known, and the rescue or recovery operation can factor in such elements as time, depth and current at the victim’s point of entry, Hendrick said.
But the “realistic environment” also means figuring out how to get onto the thin ice, where to place the tenders (non-diving assistants), and how the victim or property will be safely brought back to shore. “How to stay alive” and “be reflexive” in diving are things that can be trained and practiced, he said.
The most important thing for divers is breathing. It is absolutely necessary that divers have a quick release pony bottle of air available for use should the main scuba tank fail or run out. As the first backup, it can be used for self-rescue or for the diving buddy or victim. It is a total, redundant breathing system.
Diving with only the octopus mechanism in the scuba system is not enough, Hendrick said. There must be a backup system as well because an equipment failure could be catastrophic in its effect, causing death or injury to the diver. “Gear checks won’t predict all equipment failure,” Zaferes said.
For example, some dives occur in black water, where visibility is zero and problems cannot be easily seen. Or the water may be so cold that the octopus in the scuba system will freeze. A pony bottle helps ensure there is air even when the main equipment fails because the pony bottle is another air source and can be left with a buddy or victim, while an octopus mechanism cannot.
The pony bottle needs to be readily available with a quick release and easy to use through ice gloves or in zero visibility. “The pony bottle is not an entanglement hazard if worn properly,” Zaferes said. The hose should be under the arm, not dangling over the arm.
Self-rescue should be practiced at least once during all training sessions, and even up to five times, she said. The practice should include how to reach for cutting tools, how to don and clear the mask, how to breathe on the pony bottle, and how to pull the mask up and bring up the pony bottle. “Use the pony bottle on every dive or else you forget it’s there,” she said. Practice should be on land and in water so that movements and thought become reflexive actions in self-rescue. There must be training in the use of the pony bottle.
For example, at the end of a practice dive, have the divers ascend on the air supply in the pony bottles. And, she added, if they fail to do so, have them re-do it three times to reinforce the lesson. “Emergencies are the end of the dive,” she said. Nothing else can proceed except coping with the emergency. It is only through training that divers will learn how to stay safe.
Zaferes said the number one nemesis of public safety divers is entanglement. That entanglement could be within a submerged vehicle, in fishing line, on a submerged object, etc. All divers should carry at least two cutting tools. Require that they be carried even on practice dives—again, to reinforce the lesson and to practice retrieving and using the tools. “You don’t need a $70 dive knife,” she said. Even simple cutting tools will do, but they must be carried and they must be easy to retrieve and use.
Divers should train in communicating by headset and by rope signals if entangled. Calmly breathing on the pony bottle will help the diver avoid panic or drowning if the main air cylinder runs out while he’s extricating himself or waiting for help. “Practice cutting under water,” Hendrick said. Practice in clear conditions, but also in black water and while under a time limit. Even a simple or inconvenient entanglement could cause panic in a diver if he has not practiced how to cut away an entanglement.
Hendrick noted that most public safety divers have fewer than 18 dives in their log, so practice is vital not only to learn a process, but also to “stop, breathe and think” their way through anything that might occur in a real situation. Without such practice, their impulse may be merely to “react,” and that reaction could be something deadly such as panicking, holding their breath, etc.
Zaferes added that having at least two cutting tools provides backup. In some situations, it is impossible for a diver to dive deeper and get the tool he dropped. Instead, the diver should respond reflexively by using the other cutting tool(s) that he is carrying. Cutting tools should not be carried or stowed on the legs, Zaferes advised.
“It’s the single furthest reach from your hands,” she said, and may be out of reach if the diver is entangled. Keep the cutting tools within the triangle area of the body from the navel to the shoulders. Build a pouch in the wetsuit or drysuit and stow the knife or shears there, or build a pocket or pouch onto the BC harness so that the tools are easily accessible.
Zaferes emphasized that all members of the dive team should carry the cutting tools in the same place so that if a buddy needs to assist another diver, he can reach the tool even in zero visibility when only the sense of touch is reliable. If a diver has a personal preference for a certain location for a cutting tool, make that a third tool. The other two tools are kept in the same location where all the other divers have theirs.
For practice, take fishing line and tie it onto the diver’s equipment anywhere and in multiple places; then have the diver descend and cut off all the pieces. On land, while he is dressed for the dive, have the diver demonstrate reaching for the cutters. He should do so without looking. Zaferes advised that if the diver looks first, have him do the demonstration of reaching five times without looking. Again, it is to reinforce reflexive action.
Another exercise is to place fishhooks in neoprene and have the divers practice, during their training sessions, cutting off the hooks in black water without looking. Because rebar can be present near piers or bridges or where construction materials have been dumped, divers should also practice cutting rebar under water.
Divers should know how to cut fishing line, wire, barbed wire, rope, zip ties, hoses, rebar and other hazards that could entangle. Practice should be staged in different settings, such as at the bottom of a body of water or in a box suspended in water a few feet below the surface. The diver should practice not only with bare hands or thin gloves, but also while wearing the thickest gloves he might be using on a dive.
Zaferes added that when choosing dive suits for the team, you should ask the manufacturer for the actual lab test results, not just the advertising the manufacturer issues. See if the suit is able to withstand rebar, barbed wire, etc.
Divers should practice taking off the BC without looking, bottom to top, then shoulder straps, and then bringing one arm inside the BC (“chicken wing” style), then using the other arm and taking off the BC. Don’t allow the diver to take off the BC as though taking off a jacket (off the arms on both sides and letting it fall back). “Properly teach everything from the first time,” Zaferes emphasized.
Divers need to learn (and practice) that the first piece of equipment to be taken off is the weights. “Ninety-two percent of divers killed still had their weights on,” said Zaferes. With BCs that feature integrated systems that contain all the weight, she advised wearing one-third of the weight on the weight belt and the rest in the integrated system. She added that many women divers need more weight in front while men need weight to the back. Some BCs allow a change of location of the weight.
Divers should also practice rescuing another diver or victim who has run out of air. Zaferes said you must put the regulator by the victim’s eyes so that he sees the air bubbling, then put it in his mouth. Having the hose under the arm can help prevent the victim from ripping off the rescuer’s regulator and hose in desperation for air. A small, bright pink mouthpiece is best for visibility and ease of use.
Due to the harsh conditions of most public safety dives (as opposed to sport diving), drysuits are favored for both warmth and protection from contaminated water. But divers must practice what to do if the drysuit overinflates: disconnect, dump and flare, and practice that with gloves on, too. Zaferes noted that the drysuit neck seal must be folded inward in a “reverse turtle neck” fold to prevent possible injury to the diver from a fall in heart rate or blood pressure due to the pressure of the neck seal.
Hendrick stated that public safety dive teams that are strapped for money should not put their funds in communications but rather in pony bottles and cutting tools. He pointed out that divers with communications systems tend to chatter and not pay full attention to their safety and search work. And divers often hold their breath to hear what others are saying and use more air (breath) to talk, thus depleting their air faster.
Instead, use rope signals from the diver to the tender (each diver has his own tender) and practice what each signal means. “Don’t rely on communications,” Hendrick said. Use rope signals, and use the communications system only as a backup to check that each diver is breathing. A tender can easily compute, within 100 psi, how much air his diver has left.
A dive team must be composed of people who are physically and mentally ready to dive and who have the equipment ready for the dive. “Ask, ‘What can go wrong here?’ of every dive,” Hendrick said. There might be 15 feet of thick grass that could entangle divers. There might be rocks into which divers could be jammed by the current. There might be a failure in the communications system. There might be fishing line and hooks off the pier or dock. Hendrick said you need to ask, “Do we have a hands-on, practiced, proven, practical contingency plan for that problem?” If not, the dive cannot proceed.
When deciding on a dive team’s operation, Hendrick said, “The strong may not survive,” so don’t follow the tendency to put the strongest diver in and let the weakest diver be the backup. That is because if the strongest diver is in trouble, the weakest might not be able to help. “If only one diver can do the work, you shouldn’t get in the water at all,” he warned. “The best diver should be your last diver.”
The team should be composed of (at least) the primary diver, the primary tender, the backup diver and the backup tender who is also the profiler. The profiler will monitor breathing rates, distance out, direction and coverage of search sweeps and turnaround points. The backup tender is also the keeper of maps and timers. The backup tender is, thus, paying attention to the dive operation.
Also, the next search will be better because with the backup tender’s information, the team will know of debris, grass, turning points in the sweep pattern, etc. The information will determine where the next dive goes and how the previously searched area was secured. Tenders should have digital cameras for enhanced documentation. GPS waypoints may not be accurate enough for putting a diver less than eight feet from the same spot to be searched again.
Also, if the search is in the ocean, a spot once on land at low tide may be under water at high tide. Documentation must be effective and accurate as to the pattern done and the areas searched.
Tenders also keep track of the divers’ physical and mental states. Tenders can observe such things as repeated resurfacing of the diver or increases in breathing rates (know the norm for each diver’s respiration rate). As a guide, eight to 10 breaths per minute is an experienced and comfortable diver, 11 to 13 breaths per minute is a medium-experienced and comfortable diver, and 14 to 16 breaths per minute is a new diver or someone not comfortable. Deviations from what is normal for a diver may be a sign something is wrong. The tender should document breathing rates every five minutes.
Rope signals should be used, and the rope should be measured and marked so that distance is easy to calculate. The diver should face the rope and thus be facing the tender so the diver won’t have to ascend to see where he or the tender is.
Sweep patterns must be set (and practiced) so that the team knows how and where to search. The pattern might be a box, arc, “dock walk” or other shape. “The average team has no idea that they missed certain areas,” Zaferes said. Generally, divers should go no further than about 125 feet from the tenders and no deeper than 60 feet, so part of the site plan should include where the tender can move to keep in communication via rope or headset with his diver.
Zaferes added that it is good practice to teach tenders to hold the remaining rope bight in a figure-8 and not put their hand through a coil. This could trap their hand and pull them into the water if the current were swift, or it could injure their hand if the rope coil were to tighten.
The pattern is tender directed, not diver directed. That way, the divers can cover the full site to be searched. A solo, tender-directed diver using rope communications can often cover the search area better than two divers. Search efficiency is important, and a solo diver can be accurately documented and patterns can be repeated, if need be.
The diver wears (under the BC) a harness for the rope, and the rope is attached with a carabiner, not a snap shackle. Signals are sent via taps on the rope with the fingers (by the diver or tender). The rope should be held so that it drapes over the top of the hand between the thumb and first finger.
Hendrick said this provides the diver and tender more sensitivity to the signals being sent. “The better you get at it, the more comfortable the diver is and the easier it is to work,” he said. Signal without pulling the diver from the area being searched, but keep the line fairly tight. It should be a wrist flick of the rope, not a jerk on the line. “It’s all about how [to] make everything a little bit slicker. It’s the little things,” he said.
Divers should swim out to the search area on their sides. They should search only about 20 minutes, with a possible five-minute extension, depending on air supply, of course. The same goes for the tender. Both will be fighting fatigue, dehydration and cold in poor weather/water conditions. A diver rotation allows everyone to rest and keeps everyone motivated that the search object will be found.
The maximum current for safe diving from shore should be no more than one-half knot, Hendrick said. Measure currents in knots, not volume/cubic feet per second. Throw something into the water, watch it and time its travel. At approximately 6,000 feet per nautical mile divided by 60 minutes, 100 feet per minute equals one knot. If a shore dive is out of the question because of the speed of the current, a boat dive will be necessary, but the boat must be anchored sideways to the current, slightly off center to the current (not 90 degrees to the current).
That placement of the boat creates two eddies near the fore downstream of the boat, and also downstream at the center of the boat’s stern. Those eddies provide a safer diving environment. Hendrick said no diver should be deployed over the stern, nor should a tender work from the stern even if the boat has an inboard motor.
The rope should be no longer than 150 feet. A longer rope will create “drag” which can cause diver fatigue. That drag will also affect the accuracy of the search pattern. A rope that is too long will not give strong signaling ability, and it might snag on something. The rope must have narrow wrapped duct tape marks every 5 feet. Twenty-five feet can be marked by one wide duct tape wrap and one narrow wrap; 50 feet can be marked by one wide and two narrow; 75 feet by one wide and three narrow; 100 feet by two wide; 125 feet by one narrow and two wide; and 150 feet should be marked with two narrow wraps and two wide wraps. The duct tape should be replaced every five years or less, depending on wear.
Knots should not be used in the rope to mark distances because knots can snag on something, create drag or even move as the rope becomes saturated. The rope should be checked before use with a measuring tape. After use, the rope should not be coiled because coils have “memory” and will set in the rope. Instead, just pull the rope back into its storage bag, without coiling it.
Divers searching for a small item should search just beyond their shoulders about 1 foot. At the bottom, their hands should be to the front and work through the debris and sand in a waving motion, with the fingers wiggling to feel what is present. As the hands move apart, the fingers feel the bottom, and as the hands are brought back to the center, the fingers feel deeper into the sediment.
Divers being debriefed after a dive must be asked if they are 100 percent sure that the item is not where they searched. Divers must be honest about being cold or doing a cursory sweep or not searching where there were rocks. Such information means there must be a research of the area not done as well as other areas.
Just as with all other skills, searches should be practiced. “Salt” a search area with object(s) to be found. Also put two or three smaller test objects such as a carabiner, clay pigeon, marked quarters, etc. on the silt. The test objects and search objects are to be retrieved. Hendrick pointed out that people tend to search too quickly and cover an area too far or wide.
The water is the “hot” zone, the operations zone is the “warm” zone, and the staging area is the “cold” zone. Pre-assemble the equipment and BC so that everything is always ready. The air is turned on before the tank is taken from the vehicle. If the hose blows, do not use it. Divers should not be suited up until the equipment is checked. The air should be already turned on in the cold zone/staging area. The diver and the tender must check the BC assembly on the ground, and the tender should check the fully dressed and ready diver.
If there are enough people on the team, a supervisor or safety officer can check the divers at the warm zone. If there are not enough people, other tenders check the diver. The tender should be checked for equipment needed and gloves. The final check is in the water at the bubble check, when a leak might be seen in the water that was not heard on land.
With practice, said Zaferes, all of these steps can be done within a couple minutes to get the divers out, but also done with safety. Divers wear a harness to which the rope is attached. The tender, not the diver himself, should put the harness on the diver. The diver should take a breath and hold it, placing his hand in the strap against his chest. Then the tender should cinch down the harness. The BC is worn over the harness.
Empty air tanks should be placed so that the nozzle points away from the water. Filled tanks should point to the water.
Fins should be tested to see what they can do under a load. Zaferes said split or hinge fins are not generally as good as solid fins. The diver must be able to kick in any environment, even in current or when carrying a load such as a body. Most split or hinged fins give power only on the down stroke of the legs but not on the upstroke. A solid fin gives economy of movement and speed more easily. The fin buckle straps should be taped with duct tape to prevent them from catching on anything.
Searches for evidence require certain strategies to assure that the evidence is admissible in court. Hendrick advised that the evidence documentation should state when the item was found and should be “marked” by references to points on land. The site can be drawn and measured; there might be a buoy to mark it, or a GPS reading can be made.
Hendrick said the next step is to use a thin sheet of steel and etch on the date, case number and the diver’s number. Put the evidence in a box, then roll duct tape over the box. At court, the defense’s divers can be given the location of the steel plate at the site where the evidence was found. If the object is not found, the search pattern must be repeatable, meaning a tender can accurately document where the diver was (and is) at all times.
“Train for the real world, not ease of movement,” Hendrick said. “Have a real plan. Train for it. If you don’t have a plan, don’t go in.” Stephenie Slahor, Ph.D., J.D., writes in the fields of law enforcement and security. She can be reached at firstname.lastname@example.org.