Electronics and Maps
By Vernon Summerlin

Not since peanut butter and jelly have two things gone together so well.
Maps and depth finders are a combination every serious angler employs.
The term electronics is not a succinct one but it has become the buzzword
that stands for depth finders of all sorts. Many of you have other
electronic devices and accessories to aid you in determining when, where,
and how to locate fish. Oxygen and pH meters, thermometers, GPS
navigational systems, radios and telephones to contact other anglers, and
trolling motors all have electronic components and could be considered part
of your "electronics" arsenal.
Depth finder is a term that stuck with me years ago but some people call
the electronic wizards by other names such as depth sounders, fish finders,
flashers, graphs, sonar, and so on. I first became aware of depth finders
in the 1960s. Back then flashers were the rage.
Flashers are still used but mostly as an in-dash device to show you the
bottom as you speed along the lake. This piece of electronics is a clock
face with a light showing up at the 12 o'clock position to indicate the
surface and a moveable light to indicate the bottom and objects in between.
The paper graph was the next depth finder into anglers' boat. It was the
cat's meow. Its sharp definition of the bottom depicted by a gray line (or
white line), the inverted Vs representing fish (even if they were only six
inches off the bottom) and an almost true picture of brush, trees, and
rocks were printed on paper to become a permanent record. This was and
still is an excellent but expensive piece of equipment.
The paper graph required much more attention than the simple flasher.
Paper and toner (ink) had to be restocked as well as cleaning the carbon
from inside the chart maker. This, however, was a small price to pay for
the great detail it provided and, most importantly, the fish it located.
Then came the liquid crystal graph (LCG), recorder (LCR) or display (LCD)
with an ever-changing image like the paper graph. But it has no paper to
move across the front or to replace (no permanent record either), no toner
and no lights to interpret. The next generation of electronics was a boon
and a blessing.
An LCG is easy to read and maintain. It works at high speeds and many have
a variety of programs, including 3-D pictures. Several generations of LCGs
have passed with improvements but the basic picture is the same.
About the time LCGs came along so did the video screen. Not much different
from your TV screen, it offered clear pictures below the surface comparable
with paper graphs and some units could provide print outs. Some had colors
representing signal strengths. These units are expensive and haven't caught
on with freshwater anglers.
Among the later generation of depth finders is the Sidefinder by Bottom
Line. This innovation lets you see what is between you and the bank by
operating horizontally. There are even portable units for bank anglers.
The one thing all these devices have in common is the transducer.
This is the sending and receiving unit. The transducer sends out a constant sound
wave that is reflected by the bottom and objects in between. The period of
time between sending and receiving is translated into flashes of lights on
a flasher, dark pixels on a LCG or lines on a paper graph. The strength of
the returned signal will show up as a thin to thick line of light on a
flasher, a small to large area of dark pixels on a LCG or thin to thick,
light gray to dark black lines on a paper graph.
The transducer is designed to send out signals in a cone shaped pattern
and is rated by degrees. A cone angle with a tight pattern may be eight
degrees or less and a wide pattern may be 36 degrees or more. A 16- to
20-degree cone works best in most freshwater situations because most of our
angling takes place in less than 30 feet of water.
If the bottom is flat, your transducer will read a circle and give you one
red line on a flasher and a straight line on LCD and paper graphs. The
narrower the cone angle, the smaller the diameter pattern will be read.

Heedless to say, the latest generation of computer based graphics is much
better than a few years ago and a look at the size of the instruction book
lets you know there is a lot more to these units than looking for fish
symbols. You can zoom in on certain depth ranges, there is an alarm to
indicate shallow water, an alarm to let you know a fish is spotted, a
temperature gauge for the surface and many more features to feed you
information. Add to this the global positioning system that is available on
some units and you can be directed to the exact spot you caught fish last
week or last year. But that's another story.
It takes time to learn how to use all of the features, but lucky for us,
most of these units have an automatic function. We turn it on and it's set
up to work without us laying a finger on another button.
Electronic depth finders are among the most useful tools an angler can
have but the topographic map is another tool that will put you on
out-of-sight fish, and I'll talk about maps in a future article.