Commercial diving companies and explorers are among the wide range of groups acquiring magnetometers to help in their underwater search operations. Magnetometers are super sensitive instruments that detect iron and steel at hundreds of feet away. These devices assist in array of tasks which include; hunting for shipwrecks and artifacts, locating and following pipelines, looking for lost tools and equipment, tracking down weapons and explosives, pinpointing the position of anchors and moorings, and finding sunken vessels and submerged vehicles.
One organization employing this technology is Great Lakes Exploration Group. The group’s president, Steven Libert, has spent the last 28 years researching the history surrounding Le Griffon, the first European ship to have sailed the upper Great Lakes. Le Griffon was built by the legendary French explorer Rene-Robert Cavalier, and was a vital link in LaSalle’s supply route between Niagra and Illinois. It was also one of the 8,000 ships lost in the lakes. In 1679 Le Griffon went missing while transporting men and supplies needed to support LaSalle’s effort to expand exploration of the Mississippi River. During a routine dive in 2001, Libert came upon what he believes are the remains of this historic vessel. With much of the ship entombed in the lake bottom, some high tech equipment was needed to verify his find. Libert contacted JW Fishers, a specialist in underwater search systems, for some advice and equipment. It was decided the PT-1 pinpointing magnetometer would be the best choice as it could easily locate individual ferrous artifacts even on a wreck site littered with many iron objects. Using the PT-1 Libert has located what he believe is one of the ship’s iron rail guns and marked its position for future excavation and recovery. To protect the scientific and historic value of this incredible find, a partnership has been established with the state of Michigan and the Republic of France. Officials are eager to visit the site as soon as weather permits.
Another explorer utilizing the magnetometer is professor and maritime archaeologist Greg Cook at the University of West Florida in Pensacola. “The thrill of discovery is what I love about archaeology” says Cook. “When you pick up an artifact that is more than a century old, its like travelling through time”. The professor works with the university’s Archaeology Institute, which is both an educational and research facility. Part of their mission is the examination of historic and prehistoric sites, both on land and underwater. In addition to a professional staff of nine archaeologists, the institute has artifact conservation labs, exhibit space, and lots of special equipment including remote sensors for the marine environment. One of these devices is Fishers Diver Mag 1 hand-held magnetometer which can locate a large wreck at more than a quarter mile away.
Archaeologists and explorers are not the only ones working with magnetometers. Commercial diving and marine service companies have also discovered the advantages of using these powerful detectors. When San Diego Gas and Electric needed to track some gas lines running under San Diego Bay, the operations supervisor Dan Carr turned to Fishers for guidance. Because the pipe was buried 12 to 15 feet under the ocean floor, the Diver Mag was recommended as the best option for this operation. With assistance from the commercial dive team at CW Divers, Carr and his crew were able to follow the gas line’s route across the bay. He reported, “The mag worked good. It’s so powerful, when we got close to shore, it even detected a nearby steel pier ”.
Florida based Underwater Engineering Services has extensive experience in marine works including the design, inspection and repair of ocean outfall pipes. One of the tools the company uses to locate and track these lines is the PT-1 magnetometer. Project manager Randall Bazemore likes the mag’s ability to pinpoint the exact position of a pipe, even when other large ferrous objects like bridges or steel reinforced seawalls are in close proximity.
Great Lakes Dock and Dredge (GLDD) based in Illinois is the US dredging industry leader in the creation, restoration, and reinforcement of shoreline protection systems. The severe weather of the last decade has focused lots of attention on the shoreline for the protection it provides coastal communities and importance of the seashore ecosystem. One their recent projects was a $36 million beach replenishment operation in Nags Head, North Carolina. Since beginning the project, GLDD’s dredge Liberty Island has pumped more than 800,000 cubic yards of sand from offshore back onto the beach. To ensure the dredge does not strike an underwater pipeline or get damaged by metal debris, a magnetometer survey of the area is extremely important. To assist in this effort, GLDD acquired Fishers Diver Mag 1 to help clear the area.
A few of the other universities and companies using Fishers magnetometers are International Association of Diving Contractors’ member Mainstream Commercial Divers, Korea’s Daewoo Shipbuilding and Marine Engineering, environmental and infrastructure services giant Shaw Group, University of Indiana, University of Florida, Algosaibi Diving in Saudi Arabia, Bekk Solutions in Hong Kong, and the US Navy’s Special Clearance Team 1.
For more information on the Le Griffon project go to www.greatlakesexploration.org.