By calculating the amount of time between when the sound wave was sent and when it bounced back, it measures the distance and shows it on the screen. If the wave doesn’t encounter anything on its way, it reaches the bottom. If the bottom is soft and it’s just mud and weeds, the signal gets absorbed. A rock bottom will reflect a stronger signal back.
Detection range (depth) of a fish finder depends upon the frequency used for ultrasound transmission. In principle, the higher the frequency of ultrasound, the shorter the propagation range can be. The wavelength of high frequency ultrasound is short, and its directivity angle is narrow, which enables detailed searches, but it attenuates significantly while travelling through water. Low frequency ultrasound is characterised by its long wavelength, wider directivity angle and high level of tolerance toward underwater attenuation, hence enabling wide-area-searches in deeper water. To summarize, you can choose low frequency if you are searching in deep water and high frequency if you are conducting a detailed search in shallow water. Further, when using low frequency ultrasound, you may be able to conduct more precise deep-water searches by adding an optional Power Adapter, which amplifies the transmitter power to a few kilowatts. Please note, however, that when using the Power Adapter, a dedicated transducer capable of handling higher transmitter power will be needed.
Patrick Morrow is a true fisherman, starting at 4 years old, fishing for bream in his small home lake.This initial childhood fun turned into an almost full-time hobby, often traveling the country to find out new exciting waters to fish in.Favorite species to catch are pike and king salmon. When he is not fishing Patrick is a freelance writer and editor for outdoor blogs.
A fish finder is a sonar instrument that is designed for the specific purpose of detecting fish underwater. It does so by detecting reflected impulses of sounds energy. All the electronic impulses that are reflected off fish are converted into information that is then display in graphic rendition on the screen of the fish finder. In addition to locating fish, these units also measure the depth of the water, locating underwater debris, and bottom structure. The image on the screen of the fish finder can represent just one fish in the form of a small icon or with a series of arches.
Fishfinders operate using a single frequency transducer, dual frequencies, multiple frequencies or a broadband CHIRP system. In general, higher frequencies give the finest detail resolution, the least background noise on your screen and the best view from a fast-moving boat, but don’t penetrate as deeply as lower frequencies. Shallow-water inland anglers generally choose higher frequencies of 200kHz, 400kHz or 800kHz. For maximum depth, use lower frequencies. We recommend 200kHz or higher (up to 800kHz) for water depths up to 200' and 80kHz or 50kHz for deeper waters.
The size of the area you’re scanning will be affected by the angle of the cone. A wide beam cone scans between 40°-60°, meaning you’ll be covering a large area. A narrow cone will scan between 10°-20°. So make sure you’re aware of whether your fish finder is using a wide or narrow cone when you’re looking at the data on your screen. The Deeper PRO and PRO+ have wide and narrow beam scanning (55° and 15°), the Deeper START has a medium/wide beam (40°). One other point to remember about how you sonar works is that it is constantly sending and receiving data, which means your display will be continually scrolling. The current scanning data will be on the right – the further left on the screen, the older the data.
Depending on where you fish, sometimes the difference between finding a hot channel where you can always count on the fish to return during a certain time of day and absolutely nothing can be just a few feet. If you’ve ever fished for walleye, you know what it’s like to find those feeding channels or to have the days where you just can’t quite make it work.
There are a lot of good reasons to make sure your fish finder has GPS built into it, with the biggest being improving your fishing techniques and mapping all the data you could want as a fisherman. Each of these options have some great benefits to them, so pick the one that is in the right price range for you! A good rule of thumb is the more you pay, the better mapping options you are going to get, so please remember this if that is an important feature for you!
Fishing traps are culturally almost universal and seem to have been independently invented many times. There are essentially two types of trap, a permanent or semi-permanent structure placed in a river or tidal area and pot-traps that are baited to attract prey and periodically lifted. They might have the form of a fishing weir or a lobster trap. A typical trap can have a frame of thick steel wire in the shape of a heart, with chicken wire stretched around it. The mesh wraps around the frame and then tapers into the inside of the trap. When a fish swims inside through this opening, it cannot get out, as the chicken wire opening bends back into its original narrowness. In earlier times, traps were constructed of wood and fibre.
The best rated fish finder, Lowrance Elite-7X, features one of the biggest screens among the models that have made it to our list of 12 top fish finders. The 7 inch widescreen offers excellent brightness, contrast and resolution. This allows viewing details even in bright sunlight and at a wider angle. The screen and keypad have an adjustable backlight for better viewing and usability at night and daylight.