Whether you’re a seasoned angler looking to upgrade or a first-time boat owner, choosing a fish finder can seem daunting.
There are countless models available, and they’re each suited toward certain fishing conditions.
When you throw in the technical jargon with the plethora of options, trying to decide which fish finder is right for you can make your head spin.
This guide will help answer questions about fish finders and sonar technology – before you shell out money to buy one.
How they work
Let’s start with the basic technology behind fish finders.
Fish finders provide critical information for anglers. They show water depth, temperature and the contour of the bottom. It also locates structure, like rocks or sunken trees, and fish.
Fish finders do this by sending a sound – or sonar – wave into the water through a transducer.
When the sonar signal hits objects like fish or the bottom, it bounces back to the transducer and relays information. The transducer then transmits this information to a screen, which then paints a detailed picture of what lies underneath the water.
Understanding this basic concept will help you decide which fish finder will best suit your needs.
Choosing the right power
Power is an important measurement used to describe fish finders. This metric, measured in RMS (roots mean squared), relates to the strength of the sonar signal.
High-powered fish finders are necessary for deep or murky waters. This will help penetrate through silt or travel a long distance to the bottom.
A 500-watt device should work for most anglers, and 200 watts will work in shallow lakes or ponds. For anglers fishing offshore, deep lakes or especially murky water, 1000-watt devices may be necessary.
Choosing the right power is only part of determining which fish finder to use. Transducers are an equally, if not more, critical component. The transducer is the device that sends the sonar wave through the water. Choosing the right one is essential to getting the most out of your fish finder.
There are several factors to consider when picking a transducer.
First, decide what type of frequency you’ll want to use. The frequency describes the sonar wave that is emitted from the transducer. It’s measured in kHz (or kilohertz). Most entry level fish finders will use a single frequency transducer. You’ll need to choose between a low frequency, typically between 50 to 80kHz (kilohertz), or high frequency between 200kHz to 800kHz.
Low-frequency vs. High-frequency
Low-frequency waves travel best through deep water. However, high-frequency waves provide the most detailed images with less noise, especially in fast-moving waters or when boats are traveling at speed.
High-frequency transducers will work fine for waters as deep as 200 feet. In deeper waters, go with a lower frequency option.
A lower-frequency model sends a wide beam, which will produce an image that covers a wider area of the bottom. Higher-frequency waves use a narrower beam, covering less area but offering a more detailed picture.
By now, you may be wondering if you can buy a transducer that emits both types of frequency. Of course, you can – but it will cost you.
The latest in fish-finder technology, CHIRP, uses a broadband signal that paints a highly accurate picture of the bottom. These fish finders provide the most accurate reading and work well in shallow water as well as depths up to 10,000 feet.
Standard transducers send a single signal directly below the boat. But there are now fish finders that send multiple signals. Not only do they send signals directly down, but they also send signals to the sides of the boat.
This technology, while more expensive, provides a much fuller look at what lies beneath.
Transducers are typically mounted on the transom of a boat. They can also be through-mounted on the bottom of large fiberglass boats.
Some anglers also choose to mount a separate transducer on their trolling motor.
Now that we’ve covered the technical details, we can discuss the fun stuff: display screens.
This what anglers use to see what the bottom looks like… and whether there are fish below the boat. Display screens are sold in simple black-and-white versions, as well as high-definition color models that offer highly detailed images. Display screens use LCD lighting, and picture quality is measured in pixels. Models with higher pixels offer high-definition images. This measurement is the most important metric in determining the quality of a screen.
Basic black-and-white displays work fine and will help anglers catch fish. If you’re looking for a device to primarily to find structure and water depth, a standard display will work fine. However, if you’re looking for more details, you’ll want to upgrade to high-definition color screens.
In the higher-end models, different objects show up in different colors. This allows anglers to tell the difference between hard and soft bottoms. Rocks and trees. Bait and fish.
Display screens also come in different sizes. Some anglers prefer big-screen displays. Others, like kayakers or anglers in small boats, go for smaller versions.
You will find that many fish finders offer GPS technology. That allows the device to also function as a map and chart plotter. These models are, as you expected, more expensive. But they offer capabilities that can help anglers catch more fish – and in some instances make them safer.
GPS-enabled fish finders serve several important roles. They greatly enhance navigation and safety. Boaters can purchase SD cards and upload maps and charts into their units for specific bodies of water.
These aren’t simple maps. They’re highly detailed charts that show water depth, bottom structure and other important details for both navigation and fishing. These charts help guide boaters through new waters, locate navigable channels or simply find new areas to fish.
Whether an angler downloads the charts or uses a standard map, a GPS fish finder allows them to know exactly where they are. If an angler is lost, they can use the map or chart plotter feature to get back home. A fish finder’s GPS function can also act as a powerful fishing tool.
Anglers can mark hard-to-find structure or other honey holes. With the spots saved, anglers can return to the exact location where they caught fish on future trips.
The chart plotter also helps when drift fishing over reefs or weed beds. Instead of anchoring or guessing where the structure is, anglers can use the GPS unit as a guide to repeat successful drifts with ease.
The ultimate deciding factor in choosing a fish finder is your budget. Basic models can be found for under 200 bucks. However, those looking for the latest and greatest can spend as much as 2,000 dollars.
Anglers can easily reap the benefits from fish finders for as little as a $100. But for serious anglers who want big, high-quality screens and powerful bottom reading capabilities, the high-end models deliver.
For fishermen looking to spend around 100 dollars, check out the Lowrance Hook-3X. It’s also a great option for those interested in kayak fish finders.
This unit offers a 3-inch color screen and can transmit both a high and low-frequency sonar wave. The low-frequency wave provides a 60-degree transmission beam, offering a wide coverage of bottom reading capability.
The unit reads water temperature, and its color screen can allow anglers to determine bottom hardness, thermoclines and different types of structure.
Double your budget and you get more fish finding capability, Garmin offers the Echo 200.
This black-and-white unit has a five-inch screen. It also transmits both high and low-frequency waves, allowing for peak performance in both deep and shallow water.
At 300 watts, this unit is accurate for in up to 600 feet in saltwater and 1,500 feet in freshwater.
The Echo 200 is an affordable, no-frills fish finder that will work in a variety of fishing conditions.
Fishfinders above these price ranges begin offering higher-quality sonar technology, GPS capability and larger, higher-quality screens.
For a little under $500, the Raymarine Dragonfly 7 offers all of these features.
The 7-inch color screen features a sleek design and a toggle switch to navigate features. The sharp design of this unit will look great in any boat.
This unit features Raymarine’s Dual Channel CHIRP sonar technology. They designed one channel to accurately find bait and game fish. The other provides a stunning high-definition picture of the bottom structure.
To boast this technology, the company publishes real images captured by their customers. There are images of sunken ships and airplanes, as well as old roads and bridges at the bottom of reservoirs.
This unit also has a built-in GPS and a chart plotter. Users can split screens to see both bottom reading channels and their location. They can also sync it with GPS-enabled trolling motors.
The Lowrance Hook-9 also offers many of these features for a great price.
This unit offers a high-definition 9-inch color screen. It has a built-in GPS unit and chartplotter that shows real-time locations and allows anglers to save fishing spots.
This 500-watt fish finder employs CHIRP sonar, using a range of frequencies to provide a highly accurate picture of the water. This sensitive sonar technology reduces noise and better separates objects. That allows anglers to know the difference between bait and game fish.
The unit’s split-screen capabilities allow anglers to simultaneously see their location and bottom scans in different frequencies.
For anglers with a bigger budget, consider the Humminbird Helix 10.
With a 10-inch, extremely high-resolution color screen, this unit provides crisp images in the brightest of sunlight. The screen quality is 1024 by 600 pixels.
With 1000 watts of power, this unit will work brilliantly in waters as deep as 3,000 feet.
The high-quality screen delivers incredible bottom reading capabilities powered by the unit’s down and side imaging. By sending sonar signals below the boat and to both sides, this unit offers anglers a complete 360-degree view of the water.
Users can quickly jump between 5 preset views or watch several views at once using the unit’s split-screen capabilities.
The unit uses both high and low-frequency sonar waves, offering versatility in deep and shallow water.
This fish finder comes equipped with a powerful GPS unit and Humminbird’s ContourXD map, which shows a topography-style view of the water. It also has a chip reader that allows users to upload other commercial maps.
The unit’s chart plotter allows anglers to see where they have fished and to track drifts. This is especially powerful when linked to GPS-enabled trolling motors.
Anglers can use the trolling motor to anchor over spots. They can also repeat drifts or troll down banks or other structure with just the push of a button.