Generally, a fish finder is used by fishermen who fish in boats. A sensor helps in shooting sound waves into the water and this is called as a transducer.
Information relating to a fish finder transducer can sometimes be a little complex to decipher. Transducers come in both high and low frequencies. 50 to 100 kHz is the range of a low frequency transducer. Lower frequency can be equated to greater depths since the sound waves in this case can travel for a long distance. 180 to 200 kHz is the range for a higher frequency model.
One important point to note is that all fish finders are designed to work only with a specific or a couple of frequencies. When you intend to buy a transducer, you need to ensure that the model works with the frequency of the transducer. This rule applies to both kinds of fish finders.
When it shows yellow, it means that the object is not as dense as the red. When you look at the screen, you will notice red arches that show up in the blue area. This is showing fish movement. The fishfinder will also show big balls of red, which usually means that there is a bait ball underneath the boat.
It uses a highly sensitive digital filtering process that enables the user to troll faster and see the fish that are under and around the boat. Also, in shallow water it cuts through the clutter and makes it easier to see the fish at that shallow water depth. This is the usual depth that the average angler fishes.
It doesn’t show the density of what is underneath the boat, the monochrome fish finder just shows the bait balls and the arches. It only shows them in black, which makes it harder to differentiate between the bottom and what is actually fish. Also, the monochrome fishfinder choices usually come in smaller size screens than that of the color fish finder models.