Using sonar properly is not that difficult, however, if you understand its most critical elements. What follows is a primer on four of the most important aspects of sonar. Learn how they work, and your sonar will not just be entertainment but also an effective fishing tool. Flashlights and Fishfinders Sonar operates by sending and receiving signals via a transducer. The breadth that sonar can view beneath a boat is greatly affected by the diameter of the cone, which in turn is a function of the viewing angles.
Many people greatly overestimate the size of the area that they can view beneath a boat.
A wide cone angle does not work well when the boat is moving fast, however, especially if you need to find individual fish as opposed to tight schools. A medium-wide cone angle is a good compromise. Use the wide angle to search for fish since you can cover a broad swath of water, and then switch to the narrower cone to better define targets. An arch is formed when you're directly over a fish that is moving through the cone. Depending in part on depth and cone angle, many fish are not directly in the cone when detected by sonar, so only a partial arch, or a flat line, is depicted.