The Ultimate Guide: How Does a Fish Finder Work?
Since time immemorial, fish have been kept away from fishermen. And throughout history, fishermen have devoted themselves to studying the habitats, diets, and seasonal rhythms of the fish species they depended on to survive, not to mention the larger species they relied on for show off! Imagining a magical gadget that would detect fish under the water's surface was wishful thinking at best.
But today, this imagination exists. It's called fish finder. Used to the best of its ability, a fish finder can augment conventional fishing skills by revealing environmental information such as water depth, bottom structure and features. He can also show you the fish, provided you know how to use it.
Interpreting sonar readings from a fish finder is not difficult, but like any skill worth learning, it requires some technique and practice. It's also hard to do if you don't have at least a basic understanding of how a fish finder works.
A Brief History of Fish Finders
Before there were fish finders, there were depth finders, which are active sonar devices that display water depth and record permanent, automatic records of measurements. It dates back to 1913, when a German inventor named Alexander Bem patented an echo sounder to measure sea depths (or obstructions to ships) using reflected sound waves.
Although fish finding tools were initially derived from depth finders, today the tools and their techniques have merged.
Operating Theory
The fish finder consists of three main parts - the power transformer, the processor and the display screen (usually the processor and display are combined).
The transducer transmits and receives underwater sonar pulses. It contains piezoelectric crystals and vibrates at a set frequency.
The processor (basically a mini-computer) interprets the information received by the transducer and converts it into digital signals. He's the mastermind of the operation, if you will.
The display displays - well - the information in a format that is easy for humans to digest. Among other things, it can be programmed to display fish icons or raw sonar data (more on these options later).
General Interpretation
Let's talk about what actually shows up on your fish finder's display and how to interpret it. Statistics such as water temperature, depth, and GPS coordinates (if your fish finder has this feature) are pretty straightforward.
But what about all of the sonar data? Although it can be a little overwhelming at first, this is where you can really start to see the bigger picture.
As mentioned earlier, you can program your fish finder to fish symbol mode, or you can just work with raw data. The choice is yours, but understanding how raw data is interpreted will ultimately help you in either situation. Let's delve deeper!
Many modern fish finders display sonar data from right to left on the screen, with the most recent data shown on the right. This may take some getting used to because the screen continues to move even when your boat or fish is stationary.
Many anglers get excited when their fish finder of boat displays four large fish, only to realize that it is the same stationary fish that was displayed four times from four different sets of sonar data. Don't be fooled! But you have to pay attention to the changing positions of the fish while the fish finder is tracking it.
In general, the sonar display on your fish finder will use color intensity and brightness to indicate signal strength. In practice, this means that harder objects (such as rock bottom) will appear thick, bold, and bright, while softer objects (such as mud or weeds) will appear with less contrast. With a little practice, you will be able to visualize the aquatic world below you in no time. Combine your fish finder's technological data with your specific knowledge of the species you're looking for to find the perfect location... and start casting or fishing!
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