Marine Unit Tips: Training Your Team to Use ROVs for SAR
Rachel Doornekamp | November 2, 2021
Search and recovery missions are dangerous for divers and time is critical. Submersible remotely operated vehicles or ROVs provide search and recovery teams with a safe and effective tool for the search and recovery of victims and/or evidence. Specializing in identifying targets of interest, victim and evidence recovery, and rapid search response, a Deep Trekker ROV can enhance and assist search and recovery teams.
When time is of the most importance, Deep Trekker ROVs have eyes in the water in seconds. In time sensitive situations, the ROV provides real-time visuals while add-on sonar allows for accurate and effective navigation in the turbid waters. Tailor-made tools such as additional lighting or grabber arms allow teams to retrieve victims or evidence.
The easily transportable and deployable robots allow teams to work effectively in remote and difficult locations. In an industry as potentially dangerous as search and recovery, the assistance provided by an ROV keeps divers safe and out of precarious situations.
Search and Rescue versus Search and Recovery
Search and rescue is an operation executed by well-trained and specialized emergency services to locate and extract an individual believed to be in distress, or in imminent danger either in a remote or difficult to access area, such as mountains, desert or forest, lakes or at sea. Search and rescue differs from search and recovery in that search and rescue is only used when there is a chance to save a life. When it is concluded that the missing person may be past rescue, the mission enters recovery mode as risk to rescue personnel in an all out effort is no longer warranted.
Underwater search and recovery specifically is the process of locating and recovering victims or objects lost underwater by divers, remotely operated vehicles and/or electronic equipment on surface vessels.
Step by Step for Body Recovery
Having a step by step plan allows teams to get searches started on the right foot. Organization and preparation is crucial for a successful search and recovery.
There are 5 main steps to body recovery;
- Speak with witnesses
- Do research to determine initial search area
- Use side-scan sonar to locate points of interest
- Use the ROV to identify points of interest
- Pull identified object up or use the ROV tether as a guide for divers
Following this basic five step outline puts teams on the right track for a successful recovery.
1. Speak with Witnesses
Search and recovery teams need to find their target in a quick and safe manner. Whether looking for a lost victim, vehicle or other evidence, it is imperative that investigations be conducted as efficiently as possible. Orderly and prompt searches are not only important for the safety of the search team, but also to provide closure to loved ones and allow any ongoing investigations to wrap up.
Whenever possible, it is important to reach out to witnesses quickly while the situation is still fresh in their minds. Any information they provide can be useful, from what type and colours of clothing a victim was wearing, to insight about any potential timelines to where someone or something may have been last seen.
Speaking with witnesses can provide teams with valuable information necessary for the planning and implementation of a successful recovery mission. While the information witnesses have will vary greatly depending on the situation, any additional details they provide can be beneficial to the investigation and recovery as whole. Perhaps most importantly, witness testimony can give teams insight into the last known location of the target to help determine an ideal starting point for search. Once the search area has been determined, search and rescue teams can move onto next steps in the recovery process.
2. Do Research to Determine Initial Search Area
A strong search plan will go a long way in helping to recover a victim or target. Perhaps one of the most important steps of the search plan is determining the initial search area. While this can be difficult to establish depending on the available information, size of the area and the situation surrounding a disappearance, the initial search area plays a huge role in the success of the mission. The best search methods in the world will not work if the search is taking place in the wrong area.
As mentioned above, witnesses can provide valuable information to help determine the initial search area. From last known areas to chance sightings, witnesses may be able to contribute valuable insight.
There are however other types of research that can be done to determine a good starting point. A thorough sweep of areas surrounding the suspected disappearance can turn up crucial evidence to help determine the initial search area. From large clues like a capsized boat or kayak to more subtle hints like tire tracks or footprints near the water’s edge, a search of surrounding areas can assist teams in determining a successful starting point.
3. Use Side Scan Sonar to Determine Points of Interest
Once an initial search area has been determined, the team must search that underwater area to locate any potential points of interest. These points of interest will later be identified more thoroughly however at this stage typically the entire area is swept with a side scan sonar to gather several points in the interest of maximizing available time.
Murky water is inherently dangerous to navigate within as a diver. Below the surface, visibility can range from a few feet to a few inches away; in some cases, the water is so dark you would not be able to see your hand, millimeters from your face. In conditions where visibility is dangerously low, murky water search & rescue operations are extremely difficult to perform. As it is impossible to ascertain the parameters of the dive area, safety becomes a greater concern for divers facing unknown and potential precarious conditions.
In turbid waters, the standard camera on the underwater drone will work similar to a human eye; they will have a hard time navigating through the water. This is where the navigational sonar systems come into play. From the surface, the ROV pilot navigates through the low visibility water solely using the sonar's heads up display (HUD); similar to how a pilot would rely on their plane's instruments when they fly through a fog. Add-on sonar allows for accurate and effective navigation and identification of targets in turbid or dark waters.
The benefits of pairing ROVs with sonar systems for search and rescue operations is clear. By using the sonar, either side scan sonar on a vessel or sonar directly on the ROV, teams are able to quickly locate the objects or discrepancies underwater that may be the target they are searching for. From there, the ROV can be deployed to verify and retrieve, or help retrieve, the object.
Side scan sonar specifically is considered to be an essential piece of equipment for search and recovery operations. Using this sonar allows users to scan large areas quickly to spot any anomalies and potential targets. There are many specific patterns search and recovery teams use to ensure that they are covering an area in its entirety - without missing any key spots. Using a known pattern is recommended as it allows the team to accurately track where they have and haven’t searched.
In order to make the most of sonar’s ability it is also imperative that teams feel confident and gain valuable experience in navigating and identifying objects with sonar. Shane Seagroves of Lee County Emergency Services noted that when it comes to sonar, “you have to practice.” When his team first utilized sonar nearly a decade ago Seagroves shared that, “every Friday morning at sunrise we were on the lake running that (sonar) looking at stuff. We looked at tires, we looked at bricks, we threw guns in the water, I put divers in the water, we threw dummies in the water, just trying to figure out what we were looking at.”
Seagroves noted the importance of keeping things straightforward and simple to maximize training, “use the sonar as a flashlight, keep it simple...we’re taking that dark black water and we’re turning it white.”
4. Use the ROV to Identify Points of Interest
Once a scan of the area has been completed with a side scan sonar there will likely be several points of interest identified. From here, teams must investigate these points of interest to determine what these objects are. Ideally one of the points of interest if the victim or evidence the team was searching for. Even if the points of interest are not the actual target they can still be valuable hints or clues that may benefit the investigation.
Identifying these points of interest can be dangerous and time consuming work for divers. Lee County Emergency Services for example, utilizes their ROV to quickly and safely identify points of interest without endangering their divers.
After scanning the area, the team rates the targets on the bottom in terms of likelihood of a match. Using the ROV, the team quickly and safely checks the targets. “You take the ROV and you can find your target pretty easily down on the bottom,” noted Seagroves. “We identify the target with the boat, so we’re using the ROV instead of having to do hops with the divers. We deploy the ROV from the boat, verify the target yes or no.”
Using the ROV for target identification allows teams to be quick and effective. Not only are divers kept safe, but the ROV can be deployed in minutes to dive safely and efficiently to deep depths without the need for additional decompression time.
Using the ROV for target identification purposes has changed the game for Seagroves, “that’s a long way from 25 years go when we were diving in black water and basically just feeling around the bottom.”
5. Pull Identified Object Up or Use the Tether as a Guide for Divers
Once the target has been identified as the victim or evidence, they must be retrieved in a respectful and safe manner. There are two key ways that an ROV can aid in the recovery; by pulling the object up or using the tether as a guide for divers.
Using manipulators and tools such as grabber arms, Deep Trekker ROVs are able to pull a target up from the bottom to the surface of the water. In this method, humans are kept entirely out of the water. This is ideal for more dangerous conditions where it would be in the best interest of divers to avoid entering the water.
More commonly, teams will use the grabber arm to attach the vehicle to the target or a landmark nearby and use the tether as a guide for divers as they retrieve the victim or evidence. This method not only guides divers but provides team members topside with a reliable way to monitor the recovery. Using a diver for recovery is still quite valuable, particularly in cases where news crews may be filming nearby. A diver can place the victim or evidence in a black bag underwater before bringing them to the surface to prevent photographs or video footage leaking. This is done out of respect for both the victim and their loved ones.
“We attach the ROV to the target and have the diver go down and do the recovery,” explained Seagroves. Utilizing this method allows the diver to follow the tether directly to the target, making recovery quicker and safer.
Ashton Davis of Houston County Rescue also uses their ROV in this manner for recovery. In the case of Kelsey Starling, the team deliberately wrapped the DTG3 around the nearest tree to use as their diving guide line. In this case Davis noted that, “having a tether really helps.”
“By far the best piece of equipment other than divers is this ROV,” shared Davis, adding that the work possible with both human divers and an ROV makes for an ideal search and recovery team. The battery life allowed for long searches in deep and potentially dangerous waters without unnecessarily tiring divers, while the sophisticated camera provided searchers with a high quality view in waters with varying visibility.
Maximize Underwater Searches with Deep Trekker ROVs
The battery-operated vehicles are designed for ease of portability. Portability of an ROV is extremely important during a search and rescue mission. With bodies of water being located in some of the most remote locations on the planet, air transportation or on foot travel may be the only access. Deep Trekker vehicles come housed in their own convenient Pelican carrying cases, allowing them to be easily transported and deployed in isolated areas.
The DTG3 is a mini observation-class underwater ROV built to provide operators the ability to quickly deploy and visually inspect within underwater environments. Battery operated for up to 8 hours with a depth rating of 200m(656ft), the DTG3 is versatile and durable.
The REVOLUTION is a completely re-imagined ROV. The patented pending revolving head allows operators to rotate the camera, manipulators and sonar all while station holding in moving water. Depth rated to 305m(1000ft) with an 8 hour battery life (including quick swap), the REVOLUTION is tough and adaptable.
With the PIVOT, portability meets unmatched power. Equipped with 6 strong thrusters powered by lithium ion batteries, the Pivot provides users with stability, power, speed and control in a portable package. With 97 degree rotating tool positioning pilots can take advantage of flexible imaging options and convenient tool manipulation from a stable platform. The 220 degree range of motion on the 1080P camera allows users to complete inspections in a timely, straightforward manner.
As always our team of experts is available to answer any questions you may have about using an ROV for search and recovery operations. When you’re ready to get a vehicle of your own, request a quote today!
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