Buying Tips from the Marine Electronics Journal
How to Buy Marine Electronics
When upgrading your electronics, the best place to start is the
fish- finder, because it is one of the most common pieces of electronics
on a boat. Here are some of the basic considerations when choosing
a new fishfinder for your boat.
Modern fishfinders not only show the depth and bottom contours,
they have the resolution and power to show the fish, vegetation,
and fish holding structure. In addition, they can be integrated with
other electronics such as GPS and radars to help you navigate safely.
All fishfinders will present this information on a graphic display. Until
a few years ago there were only two main types of fishfinder displays to
choose from: Liquid Crystal Displays (LCDs) and Cathode Ray Tubes (CRTs).
LCD technology has come a long way. Modern screens are more compact, have
better resolution (as measured in pixels), better contrast and color. As
new technology is introduced by manufacturers, the number of CRT models
available is declining.
New high-resolution TFT (Thin Film Transistor) LCD displays have
eclipsed CRTs in performance thanks to high brightness display technology
and anti-glare coatings. TFT LCDs are widely found in newer fishfinders.
Today, color fishfinders can have 640 x 480 pixels (VGA) resolution,.
the same high resolution found on CRTs.
To compare LCD displays look at both screen size and resolution.
The larger the screen the easier it is to see what is displayed.
Larger screens also make it possible to create split screens and
data windows so more information is readily available.
The number of pixels determines resolution and detail. Take, for
example, a 320 640 x 240 480 display. The first number represents
the number of pixels in the vertical column. This determines how
well the fishfinder can separate fish from the bottom or separate
suspended objects in the water column. The second number represents
the number of horizontal pixels. This determines how long the information
will remain on the screen, an important feature when running at higher
speeds. In addition, having more pixels per square inch means greater
detail on fish, schools of bait, and bottom structure.
CRTs are similar to a television screen or computer monitor. They
are available in both monochrome and full-color models. CRTs typically
use different colors to show the relative strength of the echo, making
it easier to discriminate between different types of targets. It
used to be that to use CRTs in bright sunlight, they had to be mounted
in a shaded location or used with a viewing hood. New daylight viewable
screens have eliminated this requirement and made installation easier
and more compact.
Another important factor to consider with either an LCD or CRT is
the ability to adjust the contrast for better viewing. Look for a
fishfinder that has multiple levels for fine-tuning under any lighting
Here are some other “must have”
features to consider:
• Split-Screen and Data Window options. The ability to split
the screen and show different kinds of information at the same time
makes for simpler operation. For example, on one side of the screen
you can display the entire water column from surface to bottom. On
the other you can see detailed bottom contour information.
• With a fishfinder that allows you to integrate GPS and radar
data, data windows can be set up to show speed, water temperature,
position/location and navigation data. This feature also eliminates
the need for multiple electronic displays on the boat’s console.
• Auto settings. Offered on more sophisticated electronics,
this feature is invaluable. A good fishfinder will provide clear
pictures of the water column when the frequency, gain and range control
are set in the automatic mode. As you become more experienced with
the equipment, these controls can be adjusted manually for even better
resolution and performance.
• Zoom features. The zoom feature lets you focus in on specific
depth ranges to get a better picture of underwater structure, fish
and other detail. Zoom ranges of 2x, 4x and 6x are pretty standard.
• Bottom Lock and White Line. For anglers who target bottom
fish such as lake trout or halibut, the bottom lock feature lets
you concentrate on the bottom where the fish are concentrated. The
unit will maintain this lock automatically as the depth changes without
constant adjustment. The white line feature displays the bottom as
a white line with a second band below it. The width of the second
band will indicate the bottom hardness and helps to separate fish
from the bottom.
• Scroll speeds. This feature determines how fast the image
progresses across the display screen. It is a handy feature to have
if you tend to troll at different speeds for different species. It
also lets you slow the image at cruising speeds to see fish or the
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