Multi-frequency sonar can detect various types of fish in the water. Large scanning area for better resolution. Built-in flasher ideal for ice fishing. Everything is controlled with a few simple buttons.
Depth finder does not work properly at speeds above 5 miles per hour.
The device is small and easy to hold while fishing. Built-in sonar continuously updates the data screen for accurate information. High frequencies provide detail. Way point navigation is easy to access.
Connection cables are susceptible to interference and disruption.
Built-in GPS allows for pinpoint water navigation and way point creation to mark different spots. Create and store maps with specialized software. Finding can be controlled via an app on the phone with the built-in WiFi.
Lacks basic navigation functionality.
High-resolution sonar scanner can detect different types of fish and display information on the large, clear display screen. GPS updates five times per second. User settings are highly adjustable.
Transducer size limits mounting possibilities around small boats.
Powerful, accurate built-in GPS makes it easy to navigate around unknown waters or mark spots with way points. 4.3 inch color display. Mapping software creates maps on screen. Mounting attachment is durable enough for rough weather.
Transducer does not always function properly.
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From kayaks to motorboats to commercial fishing rigs, Garmin fish finders have a loyal following among anglers of all skill levels. The company first made its name in the marine industry in 1990 with its panel-mounted GPS 100, a huge boost to navigating offshore waters. For most people, the mention of Garmin may conjure up an image of a GPS navigation device on a vehicle dashboard or a smart watch, but for anglers, the first image is that of a fish finder or marine navigation unit.
Garmin fish finders range widely in price, screen size, and features. That can make it tough to decide which is the right model for your particular fishing needs.
But never fear, BestReviews can guide you through the murky waters and help you determine what features are critical and which you can comfortably do without. Read our shopping guide for more.
A fish finder uses sonar to give you a real-time image of the area beneath your boat. It does this using a hull-mounted transducer that sends out sound waves. The sound waves bounce off rocks, objects, and fish and return to the transducer. That sonar information is rendered into data that’s displayed on a screen.
With a Garmin fish finder, anglers can locate individual fish, schools of fish, and natural features like reefs. If the device includes a depth finder, it will tell you at what depth these items can be
found. Water temperature is often noted, too.
Where Garmin stands out in the world of fish finders is with its use of compressed high-intensity radar pulse (CHIRP) technology to locate fish, a wider field of view compared to other manufacturers’ devices, and access to its detailed GPS maps.
Also, its feature-rich devices are available in a range of prices so that any angler can purchase a fish finder. Many Garmin fish finders include a GPS receiver that enables boaters to mark spots, allowing for more precise mapping of a fishing area that you can refer to again if necessary.
Additional software, such as maps of the area in which you plan to fish, can be installed on the Garmin fish finder (many models have WiFi capability, enabling wireless data transfer between the unit and a smartphone or computer). Those detailed maps (it helps that Garmin is a top GPS navigation provider on land, too) can be used to navigate and pinpoint likely spots for a good catch.
Included in the Garmin fish finder package, the transducer is the eyes and ears of the device. The way it operates is similar to a submarine’s sonar, sending out a “ping” toward the lake bottom or seafloor, and listening for the echo. The transducer is mounted on the boat’s hull in one of three common configurations:
Transom: Typically attached to the boat’s stern on the flat outside of the hull (the transom) below the waterline. This mount is easy to set up and doesn’t impact the hull, but its location next to an outboard motor increases the likelihood of interference from the screw and the motion of the boat. Transom-mounted transducers don’t perform as well when a boat is traveling at high speed.
Shoot-through: Also known as in-hull, this transducer is glued to the inside of the hull. It’s recommended for use only with fiberglass hulls because wood, aluminum, or foam-sandwiched hulls can make accurate readings difficult. However, when mounted correctly and properly tuned, this transducer returns accurate readings at just about any speed.
The latest Garmin fish finders have full-color screens that color-code the data returned to the transducer so that it’s easier to discern what’s beneath the boat: clear water, schools of fish, individual fish, and contours of the lake or sea bottom. The screen also displays a wealth of additional information, including time, water temperature, water depth, and boat speed. Some units offer a touchscreen that makes it easier to zero in and even zoom in on specific readings to look for additional detail.
Many Garmin fish finders have a global positioning system incorporated into the device. It’s helpful for locating the position of the boat in relation to other navigation points, like the lake shore or docks. It can also be used to mark waypoints for the route back to the dock.
Garmin fish finders come in a range of sizes, from handheld portable units (great for kayaks and other small personal watercraft) to larger devices mounted near the controls of a bigger boat, such as the cockpit of a motorboat. Prices vary according to the size, features, and accessories and range from $99 to $699.
Handheld: Handheld fish finders with 4-inch screens cost between $99 and $179.
Midsize: Midsize fish finders with 5-inch and 7-inch screens cost between $254 and $399.
Large: Large fish finders with 7-inch to 9-inch screens cost between $499 and $699.
Learn how to use the device before heading out to fish. Being able to properly read and interpret what you see on a Garmin fish finder screen is the only way to really get the best value out of the device. Although today’s fish finders do a good job of interpreting the various transducer signals, you need to be familiar with the device, the area in which you’ll be fishing, and which signals can be mistaken (by the device or you) for something else, such as a supposed school of fish actually being underwater vegetation.
Know the underwater environment where you’re fishing. Fish finders provide information on features below the water, such as the lake bed or seafloor, rocks, dense vegetation, or underwater debris. Because different fish species prefer different environments, knowing what the underwater environment is like will give you a better idea of what type of fish you’re seeing on the fish finder screen.
Don’t forget to bring a charger. For smaller Garmin units, consider adding a portable pack that includes charging accessories. These fish finders quickly eat up battery power.
Increase the speed of the screen scroll. This will give you a readout as close to real time as possible.
Q. My fish finder isn’t giving me much detail. Is there a way to improve what it’s picking up?
A. When a fish finder isn’t returning good data for whatever reason, try “peaking” the transducer. It’s a way to fine-tune the settings so the transducer will return a clearer picture even in difficult conditions. Do this in four steps: First, change the range to three times the actual water depth; second, increase the sensitivity until you see a second “bottom” underneath the first one on the main screen; and third, slowly reduce sensitivity until you have a pretty good read on the first “bottom” result. Finally, put the range back to its normal setting.
Q. I pick up what looks like a school of fish below my boat, stop and cast my line, but no luck. A fellow angler said my fish finder is “running behind.” What did she mean?
A. The sonar pulse that a Garmin fish finder sends out can take a little time (milliseconds) to return. If you’re underway, in a few seconds you’ll be past the spot the fish finder just surveyed. If your screen is scrolling too slowly, you may not see that school of fish until you’re well past it. Increase the scroll speed of the screen. As soon as something interesting appears at the far right of the screen, slow down the boat.