What are fish finders and how do they work?
Today’s fish finders are based on technology that was first developed some 76 years ago by the US navy. SONAR (SOund NAvigation and Radar) Before that it was called "submarine signalling". It is a type of Fathometer (from fathom plus meter, as in 'to measure'). The technology was developed to identify submarines lurking in the vast open seas and oceans. The fish finder uses active sonar to detect fish and 'the bottom' and displays them on a graphical display device, generally a LCD or CRT screen.
Sonar works by bouncing sound waves off the sea floor. It’s really just a combination of a speaker, a microphone and a stopwatch. As the sound bounces off the sea floor and returns to the sonar receiver, the distance can be measured. This is because we know the rate by which sound travels through water (4,800 fps) and depending on the time it takes for the sound to return will determine how much space is between the sub and the sea floor. The speed of sound in water depends on the temperature, salinity and ambient pressure (depth). This follows approximately this formula (del Grosso, 1974):
Some 30 years after the development of sonar, it had evolved as technology usually does and more and more detail and information could be gleaned from sonar observation of objects under water and the seafloor. Then it finally occurred to someone that this technology could be used to find fish and a whole new industry was born.
What is SideFinding and how does it work.
Sidefinding fishfinders use the same principles as fishfinders that point down. The main differences are that they send and recieve sonar from the out of the boat to the side, and that they are programmed to ignore ground clutter and display only fish. When using a sidefinding scanner, you are only picking up the fish and nothing else. Sindefinding fishfinders also emit a narrow sonar beam of 9 degrees. While this is a smaller cone of coverage, it makes it much easier to pinpoint where the fish you are registering actually are, making it easier to pinpoint them and cast more effectivly. >
The technology for sidefinders is more sophisticated than normal down facing sonar, because the interferance created by waves required additional filtering technology to nullify the interference the waves cause when using a sidefinding fishfinder.
A Sidefinder with trolling motor mounted transducer can sweep the area 360 degrees around your boat for fish. When sweeping a circle around your boat, rotate the transducer slowly to give the unit time to work. The slower you move the transducer, the more time the Sidefinder has to pick out the fish echoes.
Why use a fish finder?
Let’s face it. Sure the simple enjoyment of fishing is great in and of itself, but wouldn’t you be more apt to want to fish in an area where there is the best chance that fish are around. Or do you care that your hook is dangling in what could be the middle of nowhere like a spaceship in the vast darkness of space. A fishfinder identifies fish. Simple as that. You troll around on the water in your boat and find fish. It’s almost a type of fishing in and of itself. Once you are able to identify targets, you drop anchor, prep your rod and get to some serious fishing with a much greater chance of actually catching fish.
Today’s technology provides for a wide range of FishFinder capability. There are handheld models that can be used from the river or lake side, models that attach to your rod and reel, models that fit on your wrist, all the way up to the feature packed Lowrance LCX19C which is perhaps the most powerful fish finder on the market with every conceivable feature.
However the greatest change to the electronic fish finder has been the advent of the GPS fish finder, which allows the fisherman to navigate unknown waters with the aid of Global Positioning Systems.
At FishFinders.com, you can choose from a wide range of fishfinders we have available from some of the biggest names in the business. If you are looking for a fishfinder, we have the model for you. We scour the internet finding the best prices and provide you with a competitive discounted prices and unparalleled customer services. We want your fishfinder purchase experience to be well considered and thought out, so you get the model that will fit your needs perfectly. We have a section in our web site called FishFinder Components that breaks down the technology to define the basic functions in order to assist you with determining weather you need specific features. There is no need to buy that full featured Fish Finder if you are just fishing from the banks of grandma's pond, but that wrist or portable model may be just what you need.