The thickness of the line representing the bottom is also a great clue to bottom hardness. Here the rule is simple – the thicker the line, the harder the bottom. But, be careful – sonar sensitivity can affect how thick the line is. The Deeper display has adjustable sensitivity. So if you turn up the sensitivity to 100%, the bottom line may appear thicker, if you turn it down to 10% it may appear thinner. So practice adjusting the sensitivity and get used to judging how much the bottom thickness varies based on this.
Fish finders are incredibly valuable tools, and the more you learn about how to read them, the more successful your fishing trips will be. A key part of learning as angler is to go from trial and error to a more knowledge-based approach. Maybe you regularly catch at a certain spot with a certain presentation – but do you know why? A fish finder will help you understand not just your failures, but also your successes. And once you know this, you can recreate this success more easily.

A GPS is a must have for many fishers and having it in one unit with a fish detector is economical, space saving and convenient. Having the addition of a GPS gives you many benefits. It will give you the ability to mark hot fishing spots and easily return to them in the future, as you can mark the spot on the GPS and then track your way back to it later. These spots are called waypoints and on most units you will be able to mark hundreds or even thousands of them.
However, fish finders for professional use, i.e., those used by commercial fishermen, can make use of other frequencies. Such frequencies include 15, 22, 28, 38, 45, 50, 68, 75, 88, 107, 150 and 200 kHz. There are some special fish finders that utilize the frequency of 400 kHz, but it is quite a rare case. As you can see, there is an extensive range of configurable frequencies available for fish finders for fishery vessels, and a fish finder generally makes use of a combination of two frequencies (high and low frequencies). The selection of the frequencies depends upon the intended purposes of the fish finder, which include, inter alia, finding specific fish species; grasping the seabed condition; conducting a wide-area-search with the search angle of 90 degrees at one go; conducting detailed search for fish schools; detecting fish schools that give weak echo returns; avoiding interference/conflict with other fish finders used nearby. The searchable range (depth) and search area are dependent upon the frequency used. On the one hand, high frequency ultrasound is suitable for a detailed search, although it cannot be used for search in deep water. Low frequency ultrasound, on the other hand, is suited for general searches in a wider area as well as searching in deep water.
Do you prefer having more detailed and high-contrast visuals on your fishfinder? Color LCD options from Academy Sports + Outdoors can ensure you don't miss a single catch. With higher-quality screens, you can zoom into specific sections of the water and even target specific fish. With additional sensors, our collection of marine GPS can track the movement of fish in real time, allowing you to trail and snag them before they swim away. Academy also carries portable fishfinders as well as castable fishfinders which are great for kayak, surf or bank fishing.
The CHIRP sonar that is built into this model is second to none in terms of performance, and always gives you a clear picture and measurement of the floor and surface beneath your boat, as well as the location of the fish around it. Another feature that we really enjoy about this Humingbird fish finder is that it comes with a built in SD card slot so that you can save your favorite waypoints to it. You can even upload additional maps to your software using the SD card feature.
When compared to other finders, this screen is relatively small, but it still gets the job done. Since it’s in full color and has high contrast, you can still see everything quite clearly. The only downside is that you have to switch between menus, which can be a problem if you are trying to find fish and mark your location. Overall, it’s not necessarily a deal breaker, but it may be enough to warrant a larger screen. Fortunately, the Striker can come in bigger sizes if you want to upgrade.
The sound wave spreads as it gets further from the transducer. The wider the cone, the larger the coverage area, but the as the cone angle spreads, sensitivity diminishes. A 20-degree cone is considered a versatile angle for fishers who frequent different water depths. More advanced devices come with double and triple beams, ideal for scanning deep water depths.
Furthermore, all you need to do to integrate high quality maps and navigational data for any lake in your region is load up a microSD card with Humminbird’s Lake Master, Auto Chart, Auto Chart Pro and Navionics software suites and pop it right into the integrated SD card slot. Hummingbird’s unique software packages take the guesswork out of knowing where to fish and how deep the fish are currently swimming so you can better decide how to go about landing that trophy catch of a lifetime.
In operation, an electrical impulse from a transmitter is converted into a sound wave by an underwater transducer, called a hydrophone, and sent into the water.[3] When the wave strikes something such as a fish, it is reflected back and displays size, composition, and shape of the object. The exact extent of what can be discerned depends on the frequency and power of the pulse transmitted. Knowing the speed of the wave in the water, the distance to the object that reflected the wave can be determined. The speed of sound through the water column depends on the temperature, salinity and pressure (depth). This is approximately c = 1404.85 + 4.618T - 0.0523T2 + 1.25S + 0.017D (where c = sound speed (m/s), T = temperature (degrees Celsius), S = salinity (per mille) and D = depth).[4] Typical values used by commercial fish finders are 4921 ft/s (1500 m/s) in seawater and 4800 ft/s (1463 m/s) in freshwater.
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.

As with many products, you’ll have to pay close attention to the specific features delivered for the price, simply because the investment for combination fishfinder and GPS can range from $500 to $1200 or more. Fishfinders and GPS units are well advanced when compared to equipment used just a few years ago. Most of the time you can get excellent 3D mapping, scanning, charting and navigation at a very reasonable price. It’s not necessary to spend hundreds more unless you really want to go after the top-of-the-line unit.

As you look for a GPS/fishfinder combo, keep in mind that the best power and frequency won’t mean much if you can’t use the information. Think in terms of a computer. You can have the most-powerful and efficient computing capability, but without a high-quality monitor, the data does you little good. That’s why it’s always a good idea to spend a bit more to get a top-shelf screen.
Other devices which are widely used as bite indicators are floats which float in the water, and dart about if a fish bites, and quiver tips which are mounted onto the tip of the fishing rod. Bite alarms are electronic devices which bleep when a fish tugs a fishing line. Whereas floats and quiver tips are used as visual bite detectors, bite alarms are audible bite detectors.
Standalone fishfinder: If you just want to see what’s below, dedicated fishfinders give the biggest display and the most performance for the least cost. If you have a small boat that you use for fishing small inland lakes or are on a limited budget, a standalone fishfinder is for you. Conversely, if your pilothouse has room for multiple displays, or if you just bought a new GPS, get a serious big-screen fishfinder. You can usually add a GPS sensor later to many units, turning them into chartplotter combos.
CHIRP devices can transmit simultaneously on high and low frequencies. The lower frequency gives greater depth penetration, and it requires less power than a higher frequency signal so it generates less noise. The result is a “whisper into the water” that locates the fish without disturbing them. The higher frequency signal gives even finer detail at shallow to mid-water depths.
The image above, at right, clearly shows the bottom structure—plants, sediments and hard bottom are discernible on sonar plots of sufficiently high power and appropriate frequency. Slightly more than halfway up from the bottom to the left of the screen centre and about a third away from the left side, this image is also displaying a fish – a light spot just to the right of a 'glare' splash from the camera's flashbulb. The X-axis of the image represents time, oldest (and behind the soundhead) to the left, most recent bottom (and current location) on the right; thus the fish is now well behind the transducer, and the vessel is now passing over a dip in the ocean floor or has just left it behind. The resulting distortion depends on both the speed of the vessel and how often the image is updated by the echo sounder.
The CHIRP sonar that is built into this model is second to none in terms of performance, and always gives you a clear picture and measurement of the floor and surface beneath your boat, as well as the location of the fish around it. Another feature that we really enjoy about this Humingbird fish finder is that it comes with a built in SD card slot so that you can save your favorite waypoints to it. You can even upload additional maps to your software using the SD card feature.
The 256 color TFT screen gives a clear image that can give you readings of depths of up to 240 ft. The charge of the unit can last up to 30 hours. It features SideFinding sonar that gives accurate readings. Its benefit is that you can point it in any direction and get full coverage of the area to find more fish. The temperature feature is included.
ONE SMALL STEP FOR MAN, ONE GIANT LEAP FOR PADDLING_KIND: In the 2009 ICAST article, I mentioned a combo system that was in the new products exhibit, but wasn't available at the time of the show. It's most certainly available now, and that unit is the Humminbird 385CI. Like us, fish seek comfort, safety, and food. This unit will allow you to gather "data" that you can process in to fish finding "information".
While not every object will be as easy to distinguish, you can always get clues from the shape and also the strength of the sonar return. Notice the multiple orange sonar returns underneath the car – these tell you that this is a very hard object. The sonar scans have hit the car, bounced up to the surface of the water, bounced off the surface and hit the car again.
A fishing line is a cord used or made for fishing. The earliest fishing lines were made from leaves or plant stalk (Parker 2002). Later lines were constructed from horse hair or silk thread, with catgut leaders. From the 1850s, modern industrial machinery was employed to fashion fishing lines in quantity. Most of these lines were made from linen or silk, and more rarely cotton.[3]
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