Boat towed detectors assist salvors

These devices can locate a variety of targets including the piles of magnetic ballast stones found on many old wrecks, gold and silver bars, cannons, anchors, pipelines, cables, and various metal debris which must be removed from an area before dredging. The two primary pieces of equipment used in these operations are a magnetometer and pulse induction (PI) metal detectors. Magnetometers are super sensitive instruments that can detect iron and steel objects from hundreds of feet away. The boat-towed PI detectors locate all types of metals, while ignoring the high mineralization in the ocean environment.

Russell Bennett, an American living in Panama, is helping the country’s antiquities ministry (INAC) locate and map historic wreck sites in the city’s old port area (circa 1720 – 1859). Before construction begins on a new causeway, Panamanian officials want to know of any wrecks that may lie along the planned route. Bennett has more than 20 years experience in magnetic surveys.

Using his JW Fishers Proton magnetometer Mr. Bennett and his assistants found several sites of significance along the proposed path of the new causeway, documented their positions, and gave the data to government authorities.

Texas based Terrasond provides hydrographic surveys, land surveys, and geophysical surveys to clients worldwide. The company was recently hired to survey a shallow water oil field near Corpus Christi that was littered with debris. The equipment they were using for canal work was not adequate for this type of project. To assist in the operation the company acquired JW Fishers’ Pulse 12 boat-towed metal detector. With a range of 16 feet, and the ability to detect both ferrous and nonferrous targets, the Pulse 12 could be towed far enough from the bottom to avoid obstacles and still detect the debris that needed to be cleared from the area.

Other agencies and companies using Fishers towed detection systems are the US Army Corps of Engineers, Sitka Tribe of Alaska, Williamson Marine Services in Hong Kong, the Royal Australian Navy, Diver Marine Services in United Arab Emirates, India’s National Institute of Oceanography, and the Search & Rescue Society of British Columbia.