10 Best Fish Finders | March 2017
- led backlighting for nighttime use
- hard to see when wearing sunglasses
- doesn't work well in choppy water
|Rating||4.0 / 5.0|
- shows depth in meters or feet
- adjustable sensitivity
- receiver isn't very water-resistant
|Rating||4.1 / 5.0|
- two sonar frequencies to choose from
- must use it at speeds below 10mph
- doesn't work well in murky water
|Rating||3.7 / 5.0|
- displays boat speed data
- tilt-swivel mount
- split-screen viewing
|Rating||3.6 / 5.0|
- helpful rock and weed indicators
- easy to navigate interface
- screen is black and white
|Rating||3.9 / 5.0|
- small enough to fit in a tackle box
- battery lasts nearly six hours
- easy to identify onscreen images
|Rating||4.2 / 5.0|
- four thousand watt ptp power output
- water temperature alarm
- 180-degree underwater perspective
|Rating||4.9 / 5.0|
- budget-friendly price
- simple keypad operation
- includes a chirp sonar transducer
|Rating||4.5 / 5.0|
- internal gps antenna
- compatible with nmea 2000 devices
- supports autopilot control
|Rating||4.8 / 5.0|
Treasures Under The Sea
If you consider fishing a pastime, an interactive art form, or even a necessity to keep your business afloat, then a fish finder can be a great tool to help you realize one or all of these values.
A fish finder functions by detecting the reflected pulses of sound energy as they bounce off of objects under the water, very similar to how sonar technology operates. Most modern fish finders feature graphical displays that show measurements of such reflected sounds, the time it takes for the sound echoes to return, and the distance to the object based on that information. Fish finders send and receive signals many times per second.
Individual sound pulses are concentrated into a beam transmitted by a transducer, which takes the electrical signal from your transmitter, converts it into sonar, and then sends it out. The transducer captures all returning echoes and converts them back into electrical signals. When the transducer transmits a sound into deep water (approaching the seabed), the beam expands as it descends, thereby covering a wide range. Imagine this beam in the shape of a large triangle. The apex would be closest to your boat, while the base of the triangle would be represented by the seabed. Everything within the area of the triangle (in between the boat and seabed) represents the detection area. Depending on the consistency of the seabed, the return signal may be weak or strong. Hard, rocky sea bottoms tend to send back strong signals, whereas soft and muddy bottoms tend to absorb the signal. The fish finder displays these signal differences to make a distinction between the sea bottom and everything above it.
Wow. That's interesting, but how do I know the device is actually going to detect fish? Good question. Fish finders detect the presence of fish underwater by leveraging the air in their swim bladders. The conserved air in the swim bladder changes the path of the sound and reflects that energy back to the device, which then displays that detection as an image of a fish on its display screen.
Fish finders also function at high sound frequencies, typically between 20-200 kHz as this helps to define targets, while allowing the devices to display fish as unprocessed sonar return signals, also called arches. Low sound frequencies can penetrate deeper waters, but they may not be as powerful as the high-sound frequencies to detect specific targets.
There are several things to consider when hunting for the right fish finder. If, for example, you tend to fish in shallow waters, one that offers high frequencies is the way to go, since high-frequency signals means greater detail on your device's digital display. Other types of fish finders deliver multiple frequency options, which is useful if you're a business owner and tend to fish in a variety of different types of water.
Increased wattage works to your advantage when fishing in very deep waters because the device can display readings quickly and penetrate deep into the ocean without losing its degree of detection accuracy. By contrast, low-wattage translates to slow readings, so if you find yourself in shallow waters, then you can go with a less powerful device. On the same note, some fish finders feature sensors with auto shutoff capabilities when the device is out of the water, which is great for conserving battery life.
Having a fish finder with a clear and bright color display also makes the detail easy to distinguish in the sunlight as opposed to black and white displays.
Using a fish finder that's compact, lightweight, and capable of being mounted to your boat's hull, floated in the water, or even pole-mounted gives you the best chances for getting the most out of your device's detection capabilities.
A Brief History Of The Fish Finder
Fishfinders were dervied from fathometers, which are active sonar instruments designed for both navigation and measuring water depth. The earliest fathometers used a rotating light at the edge of a circle that flashed in sync with a received echo, which corresponded to depth. The problem with these fathometers is that they did not keep historical depth records, nor were they very accurate when waters were rough.
As early as 1948, a device for detecting fish underwater was developed in Nagasaki, Japan by the Furuno brothers (Kiyotaka and Kiyokata), who co-owned a small marine electrical company. A private talk with a fellow fisherman lead the brothers to discover that air bubbles could be used to detect the presence of fish. Kiyotaka, the older brother, started developing a fish finder using scrap materials, while Kiyokata, the younger brother, continued to bring the prototype onboard a fishing vessel over and over again to perfect the design. Kiyokata was eventually bestowed with the nickname god of sardine due to his success in finding fish schools everywhere. The Furuno brothers' innovation permanently changed the face of the fishing industry, as it transformed the industry into a scientific practice instead of forcing fishermen to depend only on their past experiences or intuition for success.
In 1957, Carl Lowrance, an avid fisherman, shared his love for fishing with his sons, Darrell and Arlen. Together, they designed the world's first high-frequency, transistorized sonar for sport fishing and boating purposes. In 1959, Lowrance introduced the first Little Green Box portable sonar unit and it became one of the most popular sonars in the world.
Today's fish finders feature state-of-the-art LCD screens, built-in GPS, charting capabilities, and integrated transducers.