Fish finder capabilities and features continue to leap a head along with electronic technology advances. Modern fish finders have certainly replaced the mentality of "that spot looks good over there". Now a fisherman using a quality fishfinder can see what is hidden underneath the waters surface. Depth, structure, fish locations, speed, and water temperature can all displayed. GPS fish finder combo units are also available which help fisherman mark and navigate within feet of stored way points.
A fish finder works by sending out an electronic pulse to a transducer which converts electricity into sound, much like a stereo speaker does. With the transducer being mounted on a boat and points towards the bottom, sound waves will travel downward until reaching bottom or other objects such as fish, weeds, and trees. Upon striking such objects the sound will then bounce back to the transducer which also acts as a microphone. When this pulse of sound is received and converted to an electrical pulse by the transducer the fish finder will then make its interpretations. With interpretations calculated the display is then updated with results.
Power - The power of electrical energy produced by a fish finder and then sent to the transducer is measured in Watts. It is important to note that the unit watts can be followed by RMS or peak to peak. To keep it simple 600 watts RMS is a larger signal than 600 watts peak to peak.
What this means to the fisherman is that when fishing deeper waters more power will be necessary than shallow water. If you are selecting a fishfinder for use in the Great Lakes or saltwater fishing it is best to choose the most powerful unit that your wallet, or significant other, will allow.
Display Screens - Large screens are easy to read but the size of the display is not the only factor that should be considered. The higher the vertical and horizontal pixel count is the more defined displayed images will be. In simple terms a pixel is a dot. The display of a fish finder will consist of hundreds of dots, both vertical and horizontal. The more pixels present on a screen, the better the display will appear and as the pixel count decreases, the more blocky or less defined the screen will appear. If purchasing a used finder make sure there are no cracks in the display.
Transducers - Transducers convert electrical signals from a fish finder to sound waves for transmitting a sound pulse to the bottom, and then receive these sound waves for conversion back to an electrical signal. A transducer is typically mounted on the transom of a boat just above the bottom of the hull.
When considering different transducers the most important aspect is cone angle. In layman's terms the cone refers to how wide of a beam is sent out from the bottom of your boat. (It starts out narrow at the transducer and widens as it gets deeper.) The wider the degree on the cone, the larger the view of what lies beneath you will receive. As you move deeper, the coverage will widen and vice versa. Keep in mind that as cone angles widen, sensitivity begins to diminish in very deep water.
Transducer cones can be purchased in ranges from 9-degrees upwards of 60-degrees, with most units falling somewhere between 16 and 20-degrees. Today multiple cone angle transducers are available. A 20 degree cone angle is an excellent starting point for most applications with smaller cone angles being better for deeper waters over 40 feet.
Portable or Fixed Mount - For fisherman that rent boats, ice fish, or go on fly-in trips portable fish finders are a option to consider. Portable fish finders can be used in a variety of situations and the compact size and carrying case make travel a breeze. These units also perform as well as fixed models.
Fixed or permanent mount fish finders certainly are choice for boat owners as the unit is ready go every time they get into their boat. Transducers can also be attached to either the stern, trolling motor, or hull in order for it to be out of the way and securely held.
GPS Option - With the affordability of the GPS, fishermen are finding many uses for this revolutionary technology. Global Positioning System uses satellite signals to pinpoint the exact location when out on the water. This technology allows you to mark the best spots and come back to them time and time again, find your way back to shore in the case of an emergency, and also map out co-ordinates of any lake through the use of mapping software.
Used Fish Finders - With prices of fish finders going up and away there's certainly nothing wrong looking at used fish finders. Unlike a mechanical device electronics really don't wear out. Just make sure the transducer, power cords, and other accessories come with the fish finder.