The question of measuring depth has always been relevant. As soon as people began moving across water and the first ships appeared, a pressing issue arose: how to determine depth in order to avoid running aground and shipwrecks?
Today, the fishfinder comes to the rescue. Its main purpose is to show the depth beneath the boat and the bottom structure. This information is extremely important because it helps to:
If you are going fishing in a new place you have never visited before, it is almost impossible to manage without a fishfinder. Of course, you can try to navigate “the old-fashioned way” — by the shoreline or ripples on the water — but that will not provide the required accuracy and reliability.
So, how does a fishfinder work, and why do we see fish on the screen? In fact, it is quite simple.
Every fishfinder comes with a sensor, often called a transducer. Most often it is small, although larger versions have appeared recently, such as structure-scan transducers. This device is usually mounted on the stern of a boat.
Its operation is based on sound waves. The transducer emits a signal, which reflects off the bottom or objects in the water column and then returns. The information received is sent to the fishfinder’s “head unit,” where it is processed and converted into an image on the screen.
How is all this displayed? If we talk about Broadband (not modern structure-scan technologies that can draw detailed reliefs and objects), the bottom is usually shown as a line. The depth of this line changes depending on the terrain beneath the boat.
Fish may appear on the screen in different ways:
Sometimes the image even allows you to guess the species of fish.
The more time you spend with a fishfinder on the water, and the more carefully you study the display, the easier it becomes to determine which fish is under the boat — predatory or peaceful. For experienced anglers, this almost becomes an intuitive skill.
Live Sonar provides high-resolution, real-time images of fish movements with greater detail. This system sends sound pulses into the water and displays in real time the fish and underwater objects that reflect these pulses.
Each manufacturer calls this system differently:
