Shallow Water Hunting; Salt-Water Hunting - Fisher Labs F70 User Manual

OPERATING MANUAL
Detecting Activities (continued)

Shallow Water Hunting

All Fisher Research Labs search coils are waterproof, allowing you to search in shallow water
to about two feet deep. If searching around water, be careful not to get the electronics
housing wet. Avoid salt spray, as it will work its way into the control housing and damage the
electronics -- such damage is not covered by the warranty.
Both fresh and salt water beaches are popular places for metal detecting. Vacationers lose
money and jewelry playing in the sand and in the water. It is usually easy to dig in a beach
environment, and metal detecting is permitted on most beaches. Occasionally you may be
able to help someone recover a piece of jewelry they have lost minutes before, this is a
gratifying experience.
When searching on a beach, it is best to either search in Autotune mode, or to search with the
discrimination level set just high enough to eliminate iron, because the value of beach finds is
largely in the jewelry rather than in the coins. You will dig a lot of aluminum trash, but the
digging is easy, and you can tell people that you are helping to clean up the beach and make
it safer for people's feet. We recommend the use of special sand scoop for recovering
valuables from the sand quickly -- most metal detector dealers sell these.
The electrical conductivity of the water itself can pose some challenges. You may get false
signals when going into and coming out of the water, making it necessary to pay careful
attention to keep the coil either in or out of the water, but not to touch the surface. This effect
may be observed in either fresh or salt water.
Salt Water Hunting
Salt water is highly conductive, and produces a strong signal which is like that of metal.
The F70 is not specifically designed for top performance in salt water, but can be used in this
environment.
If you desire to search in or over salt water, the following measures will usually be sufficient to
silence the salt water response while retaining acceptable sensitivity:
1. Set the detector to Autotune mode (At).
2. Set the sensitivity to less than 30.
2. Use GroundGrab button to balance.
3. Search in the Discrimination mode with a discrimination setting higher than 20.
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GUIDE TO METAL DETECTING