Red Government Fleet with star logo
MenuMENU
SearchSEARCH

Tech Helps Police Find Evidence Under Water

JW Fishers' submersible tools can be used to find sunken objects and spare dive teams from spending time in dangerous or frigid waters.

by Brian Smith Fisher
June 26, 2019
Tech Helps Police Find Evidence Under Water

JW Fishers' ROVs can find evidence such as firearms or even bodies under water, protecting law enforcement dive teams from dangerous current and pollution.

6 min to read


For more than 50 years, JW Fishers has specialized in the design and manufacture of underwater search equipment for police, fire and rescue, commercial, military, and other search applications worldwide.

JW Fishers' diverse product line includes diver-held and boat-towed metal detectors, marine magnetometers, underwater camera systems, remote-operated vehicles (ROVs), cable trackers, acoustic pingers, a pinger receiver, sector scan sonars, and side scan sonars. In particular, JWF's sonar systems, ROVs, and its award-winning handheld metal detectors have proven to be very useful in police, military, and fire and rescue operations.

ROVs

The flagship products of the JW Fishers video line are two high-tech, economically priced ROVs: the SeaOtter-2 and the SeaLion-2. These highly maneuverable remote-controlled vehicles each have four motors that provide sufficient power to work in ocean currents with depth ratings of up to 1,000 feet.

The SeaLion-2 boasts even more thrust with a "power boost" feature that provides the ROV with an extra burst of speed in high current situations. The 2,200-lumen LED lighting provides vivid images in low-visibility environments. The high-resolution front and rear color cameras both have pan and tilt capability, providing the topside operator a clear picture of the underwater environment. Weighing less than 45 pounds, the ROV is easily deployed and recovered by a single person.

To fit the varied requirements of public safety agencies and military units, Fishers' ROVs are available with an extensive set of options that allow them to be tailored to specific missions. Options for the system include a manipulator arm, side cameras, and sector scanning sonar (SCAN-650) technology. With a manipulator arm, the ROV can pick up a lightweight object off the bottom or carry an acoustic pinger and drop it on a submerged object. The scanning sonar mounted on the ROV allows the operator to "see" far beyond the range of the camera.

Sonar

Scanning sonar can be used very effectively as a standalone search system. Law enforcement agencies are using scanning sonar in their underwater search operations to find drowning victims, bodies of murder victims or suicidal subjects, sunken vehicles, sunken vessels, and other evidence. One key advantage of scanning sonar is its ability to produce a "picture" of the underwater environment, even in zero visibility. Using this sonar dramatically reduces the exposure time of divers in sometimes frigid or dangerous waters.

One of the reasons for choosing scanning sonar instead of a side scan system is its significantly lower cost, although it is not as effective for searching large areas. This can be a powerful argument for agencies working on a limited budget. Scanning sonar systems require a stationary deployment or mounting on another system; this is often an advantage over the larger towed sonar systems. With towed side scan technology, the towfish must be moving to create an image, whereas the scanning sonar transducer can be held in a fixed position. When searching a lake bottom that is covered with trees or large rocks, it may be difficult if not impossible to tow a sonar system. Lowering the scanning sonar, however, is simple and efficient. Deploying the scanning sonar system on a pole or cable when standing on a solid structure can be a quick and easy way to deploy it.

The sonar software has a host of features that allow the search to be tailored to the needs and preferences of the operator. The size of the search area can be selected and the operator can choose whether to scan the complete area or just a portion of it. A variety of color schemes in 256 shades are available to display the sonar images. There is a choice of step sizes, sweep speeds, and a sizing tool that shows the length and width of the target. High-resolution images are displayed on a topside laptop computer or tablet mounted in the lid of the Sonar Processor Box. Scanned data files are stored on the computer's hard drive along with the boat's GPS position, the time and date, and other pertinent data. Recorded files can be played back at any time, and small file sections and screen shots can even be copied for emailing. The included GPS allows a target's position coordinates to be instantly viewed and automatically stored with the sonar data. Optional boat tracking software shows the path of the boat as it travels over the search area and the width of the scanned area, all overlaid on a nautical chart.

A few of the many public safety units using Fishers' sonar systems are the Beadle County (SD) Office of Emergency Management, the Fall River (MA) Police Department, the Suffolk County (NY) Sheriff's Marine Unit, Union (PA) Fire Company, and the North Carolina Department of Transportation.

Metal Detection

Let's say you are looking for a discarded firearm in a body of water. Once a target area is narrowed and a dive team has been deployed, it's time to use one of Fishers' handheld metal detectors, either the Pulse 8X or the SAR-1 Search and Recovery detector.

The Pulse 8X is JW Fishers' leading underwater metal detector and has been an industry leader for the past 32 years. In 2014, it was named the top underwater metal detector in an independent study performed by the U.S. Department of Homeland Security. The P8X was compared to seven other leading detectors on the market and found to be the most economical, effective, and reliable tool for the job.

The P8X comes with everything needed to search both on land and while submerged to a depth of 200 feet. The unit comes equipped with a land handle and telescopic extension, an underwater handle, two chargers (AC/DC), a land headset, an underwater "bone" phone, and a diver's belt to hip-mount the unit.

The SAR-1 underwater metal detector was introduced in 2017. This detector was purpose-built for law enforcement and other public safety dive teams whose mission sets include locating metallic objects in low visibility environments. The SAR-1 has a streamlined and snareless design with no external wires or cables. These features make the SAR-1 an excellent tool for work in environments containing hazards. The SAR-1's 10 ultra-bright LEDs and sensory (vibration) target indicators make this unit one of a kind.

A few of the many law enforcement teams using Fishers' detectors include: the U.S. Coast Guard, U.S. Border Patrol, Missouri State Water Patrol, the Placer County (CA) Sheriff's Department, the Lowndes County (GA) Sheriff's Department, the Jackson County (WI) Dive Unit, the Detroit Police Underwater Recovery Unit, the Houston Police Dive Team, the New Jersey State Police, the New York State Police, the National Police Dive Squad in New Zealand, the Swedish Coast Guard, Japan's National Police Agency, and the Royal Canadian Mounted Police.

Editor's Note: Brian Smith Fisher is the chief operating officer of JW Fishers. This article first appeared in the June issue of POLICE Magazine.

Subscribe to Our Newsletter

More Police

Policeby Jeanny RoaFebruary 4, 2026

Addressing Fueling Failures to Reduce Operational Risks

Working to eliminate errors and challenges and increase reliability during fueling, the Madison County Sheriff’s Office has implemented RoadFlex for its 37-vehicle patrol fleet.

Read More →
Policeby Nichole OsinskiJanuary 26, 2026

PUG: When Policing Goes Autonomous

How an uncrewed police ground vehicle is providing technical assistance to the Miami-Dade Sheriff’s Office through a pilot program with the goal of supporting officers and reducing crime through increased marked police presence.

Read More →
Policeby Staff WriterJanuary 20, 2026

Applications Open: 2026 Police Fleet Innovators Award

The Police Fleet Innovators Award is for fleet operations teams that have come up with innovative solutions to common problems in law enforcement fleets. Click for deadline details, plus an award FAQ.

Read More →
Ad Loading...
SponsoredJanuary 19, 2026

Basic Tracking vs Next Generation Fleet Technology

Fleet software is getting more sophisticated and effective than ever, tying big data models together to transform maintenance, safety, and the value of your existing tech stack. Fleet technology upgrades are undoubtedly an investment, but updated technology can offer a much higher return. Read how upgrading your fleet technology can increase the return on your investment.

Read More →
a bullet board with police pictures of vehicles plus handcuffs and police tape.
Policeby Nichole OsinskiDecember 26, 2025

Police Fleets in 2025: Stories That Defined the Year

What did police fleets actually wrestle with in 2025? We highlight the most impactful stories on vehicles, funding, technology, and operations, distilling the key takeaways for fleet and command staff.

Read More →
University of Tennessee at Chattanooga Police SUV parked outdoors, displaying updated blue-and-gold graphics, police markings, and university identification.
Policeby News/Media ReleaseDecember 24, 2025

New UTC Police Cars Hit the Campus Roads

The University of Tennessee at Chattanooga Police and Public Safety has updated the graphics and branding across its vehicle fleet.

Read More →
Ad Loading...
A newly delivered red Airbus H125 helicopter marked “Sheriff” and “Erie County” inside an Airbus facility.
Policeby News/Media ReleaseDecember 18, 2025

Davenport Aviation Delivers New Airbus H125 Helicopter to Erie County Sheriff’s Office

Erie County adds its first of two Airbus H125 helicopters, boosting aviation readiness and public-safety response capabilities.

Read More →
PoliceDecember 10, 2025

Weather Protection Strategies For Public Safety Fleets

How Mansfield PD addressed weather-related risks to its patrol vehicles, and what fleets need to know about planning and specifying protective structures for similar conditions.

Read More →
Row of newly designed Indiana State Police Dodge Durango patrol vehicles parked outdoors, marking the rollout of the new fleet design for graduating troopers.
Policeby News/Media ReleaseDecember 2, 2025

Indiana State Police Troopers Receive New Look Dodge Durango Patrol Vehicles

Indiana State Police rolls out its first fleet of newly redesigned Dodge Durango patrol vehicles as 20 probationary troopers from the 87th Recruit Academy begin service across the state.

Read More →
Ad Loading...
Policeby Staff WriterDecember 1, 2025

Michigan State Police 2026 Vehicle Testing Results

2025 MSP vehicle tests revealed standout police cars, from EVs to pursuit-ready SUVs.

Read More →