Swiftwater rescue operations are inherently dangerous and fast-paced, requiring precise coordination and decision-making. The stakes are incredibly high, as victims in swift-moving waters are at severe risk of drowning or injury from debris and obstacles. When the victim’s location is known, the rescue phase commences immediately, focusing on extraction. However, in many cases, the victim’s exact location may be unknown, necessitating a structured search process. This article outlines the key search techniques used in swiftwater rescue operations, offering both detailed instructions and practical advice for new and experienced rescuers alike.

Gathering Essential Information

One of the most crucial and challenging aspects of a swiftwater rescue is gathering information on the missing individuals. River conditions are unforgiving, and victims can quickly become separated, especially in events like boat capsizes or flash floods. Rescuers must gather as much relevant information as possible from witnesses, including:

• Number of missing persons: Knowing how many people are unaccounted for helps determine the scope of the search.
• Descriptions of clothing: Bright or distinct clothing can aid in visual searches.
• Gender and physical characteristics: This helps in identifying victims, especially when visibility is poor.

The goal here is to establish a clear picture of who is missing, how they may have been swept away, and where they might be. It is critical to document all the details provided by witnesses as they can later prove invaluable in narrowing down the search area.

Point Last Seen (PLS)

The Point Last Seen (PLS) is one of the most crucial pieces of information in a swiftwater search operation. This is the last physical sighting of the victim by someone, whether it be a witness or recorded by a device like a camera. Determining the PLS helps focus the search efforts and prioritize areas where the victim is most likely to be found.

In swiftwater rescue, the PLS is essential because it serves as the starting point for calculating where the victim might have drifted. The currents, obstacles, and overall river dynamics are taken into consideration when planning the search. For example, if a victim was last seen at a bend in the river, the current is likely to have swept them towards the outer edge, where the water is faster and deeper.

Why Is PLS Important?

• Narrowing the search area: Swiftwater rescues demand quick responses. The PLS allows rescuers to focus on specific sections of the river, rather than wasting valuable time searching vast stretches of water.
• Planning resources efficiently: With the PLS, teams can allocate resources like boats, divers, or even drones more effectively. This ensures that the most critical areas are searched first.
• River dynamics: Understanding how the river behaves at the PLS can give rescuers an idea of how far the victim might have drifted. For instance, eddies (circular water movements) near the PLS could trap the victim in a specific location.

Last Known Position (LKP)

While the PLS refers to the last time a victim was seen, the Last Known Position (LKP) refers to the physical location where the victim was last known to be. Often, these two locations coincide, but not always. For example, in the case of a boat capsize, the LKP would be the point where the victim fell into the water, while the PLS might be further downstream where they were last spotted.

In cases where the PLS and LKP differ, the distance between them can offer clues about the victim’s movement. The LKP serves as the upper boundary of the search area. If the victim was in the water at this point, river dynamics (such as the flow rate, currents, and riverbed features) will help predict their possible locations downstream.

Why Is LKP Critical?

• Upper boundary determination: Establishing the LKP ensures that rescuers don’t search upstream unnecessarily. The focus can remain on downstream areas.
• Drift estimation: From the LKP, rescuers can estimate the rate at which the victim may have drifted, based on water speed and potential obstacles.

Determining the Search Area

Once the PLS and LKP are established, the next step is to determine the most probable areas where the victim might be. This involves understanding the river’s dynamics, which can be unpredictable. In general, the following factors are considered when determining a search area:

• Unlikeliness of finding victims upstream: Victims in swiftwater are almost never found upstream of their PLS because the current moves them downstream. Rescuers should focus on the downstream areas unless there are unusual circumstances, such as backflow or eddies that could push the victim upstream.
• Hazardous areas: Certain parts of the river, like bends, strainers (obstacles like trees or debris), and submerged rocks, are high-risk areas where victims are often trapped. These areas should be prioritized in searches.
• Currents around bends: Victims tend to be swept to the outer edges of bends in the river, where currents are stronger. The inside of bends, with weaker currents, should be searched later.

Challenges in Search Area Determination

One of the biggest challenges in determining a search area is the unpredictability of river dynamics. Obstacles like rocks, debris, and trees can cause unexpected shifts in the current. If the search area is large and complex, it may be necessary to divide it into smaller, more manageable zones.

Hasty Search

A hasty search is a rapid, initial search aimed at covering areas where the victim is most likely to be found. The primary goal is speed, as time is critical in swiftwater rescues. If enough personnel are available, the hasty search can be conducted simultaneously while other team members work to determine the PLS and LKP.

During a hasty search:

• Rescuers use the buddy system: This ensures that rescuers maintain visual contact with each other and remain safe, as swiftwater environments are hazardous.
• Searches focus on high-priority areas: Rescuers target areas where the current is likely to have swept the victim, such as bends, strainers, and eddies.
• Use of tools: Paddles, poles, or other devices may be employed to probe deeper sections of the water.

The hasty search is crucial for covering high-risk areas quickly, particularly when the victim’s location is unknown. However, it is not a replacement for a thorough, systematic search, which follows if the victim is not located immediately.

Disadvantages and Cautions

While swiftwater search techniques are highly effective, they come with their own set of challenges and risks:

• Danger to rescuers: River environments are hazardous, and rescuers can easily be swept away or injured by submerged obstacles. Proper training and equipment, like life jackets and helmets, are essential.
• Unpredictable river dynamics: Even with the best-laid plans, rivers can behave unpredictably, and a victim might end up in an unexpected location.
• Time-sensitive nature: Swiftwater rescues are always racing against the clock. Prolonged searches can lead to exhaustion among rescuers and increase the likelihood of mistakes.

Conclusion

Swiftwater rescue search techniques require a balance of speed, precision, and adaptability. By focusing on the PLS and LKP, rescuers can narrow their search areas and increase the chances of locating victims quickly. However, the unpredictable nature of rivers, coupled with the inherent dangers, means that these operations must be approached with caution and thorough planning.

References
Kaufman, R. (2015). Swiftwater Rescue Packet. McHenry, Maryland: Garrett College.
Walbridge, C., & Sundmacher, W. (1995). Whitewater Rescue Manual – New Techniques for Canoeists, Kayakers, and Rafter

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