If you are searching primarily for nonferrous metal (gold, silver, lead, brass, bronze, aluminum, etc.), the best piece of equipment is a metal detector (Pulse 6X, Pulse 8X or SAR-1). For boat towed equipment (Pulse 10 or Pulse 12).
If you are searching primarily for ferrous metal objects (iron and steel), the best piece of equipment is a magnetometer (DiverMag-1 or PT-1). The advantage of using a magnetometer is that it has a much greater detection are than a metal detector. For the boat towed series (Proton 4).
Also available are J.W. Fishers :
Remote Operated Vehicles (ROV) , Remote Metal Detectors, Underwater Camera Systems, Sonar Systems, Pingers and Pinger Receivers, Transponders and Interrogators
ALL ITEMS BELOW ARE SPECIAL ORDER AND MAY HAVE ADDITIONAL COSTS INVOLVED CONFIRM PRICING BEFORE ORDERING.