Dual Beam 60 degree Sonar Fishfinder, GPS with
WASS, 75 lb/thrust 36v Trolling Motor, Fuel Injected Outboards: All
this jargon can cause a typical fisherman to go insane, and when a
salesman at the fishing store is pressuring you to buy some of the
newest fancy-dancy pieces of top-of-the-line NASA quality
electronics it may just confuse you enough to run home and hide, or
even worse you may shell out hundreds of dollars for something you
don't even need. Well guess what, you can stop hiding and you can
return to the fishing store with confidence after reading these
articles on debunking the electronic facts and myths to make you an
Because there is a lot of ground to cover I am
going to break this article into separate parts. So with no further
ado, let me introduce to you Part#1 of the Electronic Dance-
Fishfinders have changed a lot over the years,
flashers and paper graph finders were at one time a luxury that a
fisherman may have on his boat. And they were relatively simple
devices. They would send a sound wave through its 'transducer' into
the water and calculate how much time it took to get back to itself
after it had 'pinged' off an object. And it could even tell you how
hard or soft the 'pinged' object was.
Today, flashers are pretty well obsolete and
graph finders have gone away with paper and have been replaced with
screens. There is also an immense amount of fishfinders you can buy.
Let's start with describing the viewing screen of a fishfinder. A
fishfinder screen is actually called an LCD or 'Liquid Crystal
Display', that term is not important, but what is important is that
an LCD screen is made up of tens of thousands of tiny dots, which
make up the picture you are viewing. When you look at a fishfinder
it will say on the packaging something along this: 320x240 Display
Resolution. The numbers denote how many dots are on the screens. In
this case there are 320 vertical dots and 240 horizontal dots. These
all together equal 76,800 dots which make up the picture on the
screen. Take a look at the below pictures.
The one on the left is a "low" resolution
picture. The one on the right is a "high" resolution picture. The
one on the right clearly has more dots making it easier to see. This
is important because if it was a graph, you can make out small
objects much easier, such as baitfish, where a "low" resolution
picture would make them very hard to see if at all. You can buy a fishfinder in many different resolutions, but be aware, the price
dramatically goes up when you get a higher resolution fishfinder. I
find a cost effective and easily read 'resolution' is 320x320 or
even 240x320. Anything lower than that I would stay away from.
Anything higher than that is better, but for the average fisherman,
it is unnecessary.
Display colours and grayscale options are
important to consider. A coloured display is very nice looking, but
also, very expensive. Grayscale is just as it sounds, it is gray
only. Unless you want to just splurge and buy the best, I would
spend my money on a high quality grayscale fishfinder rather than an
equal amount of money for a low quality colour fishfinder. Grayscale
comes in many forms; usually 16bit, 12bit, 8bit, 4bit. What this
means is the amount of shades of gray used. A 16bit screen uses 16
shades of gray, while an 8bit screen uses 8 shades of gray. The
shades are important for easily identifying bottom contours and
where soft bottoms and hard bottoms meet. Also, the higher bits make
the screen much easier to look at. Most of today's fishfinders come
with 8 bits and above. However, many cheaper models are still sold
with 4bits. If the box says "4 shades of gray" or "4 bit grayscale",
this is a tell-tale sign that this is a beginner's fishfinder and
you will likely be disappointed with its results.
Single beam and dual beam sonars can be tricky
to describe. A single beam sonar is just that, it shoots a single
beam onto the bottom of the lake and returns the signal. These
generally give a cone shape at 20 degrees. A dual beam shoots two
sound waves into the water
You see, the one sonar is 20 degrees like the
picture on the left, however the dual beam sonar gives another sound
wave at 60 degrees. This gives you 60 degrees sonar coverage from
the back of your boat. I know what you're thinking; why not just
have one beam with a 60 degree cone. Well this is clearly possible,
but the wider you make your cone, the less quality the 'transducer'
picks up. This makes it not clearly show things as well as a narrow
20 degree cone.
With this information you should be able to buy
a new fishfinder with ease and you might even be able to teach the
salesman a thing or two about the product he is selling.
In our next article we will talk about GPS
units, so stay tuned!