Shallow Water Hunting; Salt-Water Hunting - Fisher Labs F 75 User Manual

F75
Comprehensive Operating Manual & Guide to Metal Detecting
Detecting Activities (continued)
Shallow Water Hunting (continued)
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 Motion All Metal 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 a 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 F75 is not specifically designed for high 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 sensitivity in both modes to less than 30.
2. Ground balance the machine manually in Motion All Metal mode.
3. Search in the Discrimination mode with a discrimination setting
higher than 25.
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