The Ultimate Salvage Equipment
Over the last 60 years magnetometers have been credited with finding thousands of shipwrecks worth hundreds of millions of dollars. These super sensitive metal detectors, first used in WWII to locate and track submarines, have today become the workhorse of any serious marine search operation. Magnetometers or "mags" are in use by a diverse group including professional treasure hunters, marine archeologists, commercial diving companies, law enforcement agencies, and military units. In addition to finding shipwrecks, mags are often employed to locate pipelines, anchors, sunken automobiles, weapons, and unexploded ordnance.
These instruments locate shipwrecks and other lost objects by sensing changes in the earth's magnetic field. Any object made of iron or steel creates a disturbance in the field which the magnet ometer can measure. A mag can detect a major disturbance, like the one created by a large steel wreck, at a distance of a quarter mile or more. This makes it the ideal piece of equipment to use when searching a large area. Even old wooden wrecks, like Spanish galleons, have a "magnetic signature" created by the cannons, cannon balls, anchors, stoves, and other iron objects carried on board. Although the timbers have long since disintegrated, and valuable cargo is hidden under the sandy bottom, the powerful mag can detect the wreck's debris regardless of the material covering it.
JW Fishers has specialized in the design and manufacture of magnetometers for over 20 years. Currently they produce two state-of-the-art mags, the Proton 4 boat-towed model and the Diver Mag 1, a hand-held unit carried by a diver. Both mags have visual and audio readouts. The Proton 4 features an easy-to-read LCD display that is backlit for night operations and an audio alarm to alert the operator when a target is encountered. The Diver Mag 1 has an LED display for easy underwater viewing and a waterproof earphone that lets the diver know a target is being detected. Both devices employ a unique triaxial noise-cancelling sensor which allows the mag to move in any direction without heading error or dead zone. A software package is available for the Proton 4 that allows the mag readout data, the boat's GPS position, and the track of the boat over the search area to be displayed and stored on a laptop PC.
To receive a data sheet on Fishers marine magnetometers or a color brochure on all of their quality underwater search products, contact Christopher Combs at JW Fishers Mfg. Inc., 1953 County St., East Taunton, MA 02718, USA. Phone: (800) 822-4744 or (508) 822-7330. Fax: (508) 880-8949. E-mail to [email protected] or check out the website at www.jwfishers.com.
•Find Anything Lost Underwater with Side Scan Sonar
A new line of side scans is being offered by JW Fishers. The new PC side scan system displays real-time sonar images on a notebook computer or an optional splash-proof PC for small boat operation. Side scan sonars are one of the most effective tools for underwater search operations. One reason these systems work so well is that the sonar can "see" what's on the bottom regardless of water clarity. Another reason is that large areas ca n be searched quickly as the sonar beam sweeps hundreds of feet on both sides of the boat. Side scan sonars work equally well in salt or fresh water, and can be used in lakes, rivers, harbors, and open ocean.
Side scan sonars are in use by a diverse group of underwater searchers including treasure hunters, commercial salvage companies, law enforcement agencies, military units, and dive rescue groups. These low cost, high tech underwater search systems are capable of locating a variety of targets from downed aircraft to drowning victims. Law enforcement and dive rescue groups use side scans to search for bodies, vehicles lost in the water, capsized boats, and missing airplanes. Commercial diving and salvage companies employ the side scans to locate and track underwater pipelines, find lost propellers and dredge parts, search for sunken vessels, and a variety of other applications. Professional treasure hunters, and even recreational divers, are using these sonars to find both modern day and centuries old shipwrecks.
Three different models of the new PC based side scan are available from JW Fishers: a 100Khz system, a 600Khz system, and a dual frequency 100Khz/600Khz. The 600 kilohertz side scan has very high resolution over ranges of up to 200 feet, providing a 400 search swath. It is the perfect tool to search for small or soft targets and is ideally suited for police, fire, and rescue operations. The 100Khz system has a much greater range, over 1,500 feet on each side of the towfish, but less resolution than the higher frequency sonar. It is ideally suited to searches for large or hard targets covering large areas. The dual frequency side scan combines the best features of both systems. Fishers sonars have broad appeal because of their low cost and high performance. Their single frequency side scan starts at under $20,000, making it an affordable tool for just about every serious underwater search operation.
All of the new PC sonar systems come standard with a 500 foot depth rated towfish, 150 feet of cable, and a laptop computer. Many options and upgrades are available, allowing the system to grow with any user's requirements.
For more information on these side scans or a color brochure on all of Fishers quality underwater search products, contact Christopher Combs at JW Fishers Mfg. Inc., 1953 County St., East Taunton, MA 02718, USA. Phone: (800) 822-4744 or (508) 822-7330. Fax: (508) 880-8949. E-mail to [email protected] or check out the web site at http://www.jwfishers.com.
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