Fish Finder vs Depth Finder

Depth finders and fish finders are similar in many ways, but there are few features and functionalities that make them so different.

Fish finders use sonar technology to reveal underwater structures and fish schools in a high-resolution graphic display. While, depth finders, as the name implies, are used to determine water depth and display it in a digital readout.

These two distinctive devices are essential in helping anglers navigate the waters safely and find fish. Therefore, if you’re looking to increase your fishing success, you need to know the primary differences between fish and depth finders. This article will highlight the differences.

Fish Finder vs Depth Finder: What’s the Difference?

1. Different Frequencies

Fishfinders and depth finders function at different frequencies. These frequencies pass through underwater structures and are reflected to the transducer. The transducer then converts this information into images or digital readouts.

Depth finders send out low frequencies of around 50KHz to determine the water depth. They transmit this frequency on a broad beam angle of approximately 35 degrees. As a result, the frequency can travel deeper in the water, giving the device higher depth capabilities and accuracy.

On the other hand, fish finders use high frequencies of about 200KHz. They transmit the frequencies through a narrow beam angle ranging between 6 to 22 degrees. In return, the fish finder provides a high-resolution echo that is translated into visual images of the underwater contour [1].

In addition, high-end fish finders come with a dual-beam transducer, which means they can transmit both high and low frequencies. Low frequencies have a broader and deeper search area, while high frequencies give more refined details. Such fish finders are perfect for anglers looking for a device with fish finding and depth finding capabilities.

2. Fish Finder vs. Depth Finder Features

These devices come with different features that are useful in fishing. The features vary depending on how advanced the device is.

Most fish finders come with an in-built GPS, high-resolution display, maps, and different sonar technology. The GPS and the maps allow users to easily navigate through the water and find waypoints and fishing trails.

Advanced fishfinder models include side imaging, down imaging, fish alarms, and smartphone connectivity. Side imaging allows you to scan horizontally, while down imaging scans vertically underneath your boat for fish schools and other underwater structures.

Smartphone connectivity allows users to connect their phones to the fish finders, where they can control the device, record maps, and share the maps with other anglers.

In contrast, basic depth finders feature a sonar, depth alarm, and display unit. Additional features such as GPS and water temperature sensors come with more advanced models. Depth finders also come with different depth ranges for more efficiency.

3. Display

Both devices come with an LED or LCD monitor. However, depth finders display their findings in numerical value, while fish finders give a pictorial presentation of the sonar return.

You can see real-time images and videos of the water column beneath your boat with a fish finder. You can also differentiate between fish, rocks, crevices, and other structures in the water since most fish finders have a high target differentiation.

In contrast, basic depth finders display sonar interpretation in digital form. They will show you the depth of the water column in feet or meters. They also have a visual and audio alarm warning system that alerts you when you are in shallow zones, so you don’t run your boat aground.

More sophisticated depth finders have a high pixel display with more features. They allow you to view the water column in 3D with color contrast. They also offer information regarding potential obstructions and hazards under the surface, such as logs, reefs, and other obstacles.

Also see: Reading a Fish Finder

4. Capabilities

Depth finders give a readout of the bottom contour. They can determine the type of bottom your boat is passing over. Experienced anglers can interpret the sonar returns and tell whether the seabed is soft mud, grass beds, crevices, or rocks [2].

They can use this information to determine potential hotspots for fish and how deep they need to cast their lures to catch fish. They can also use it to navigate safely through the water without the risk of crashing their boats.

On the contrary, a fish finder uses sonar technology to locate fish in the water column below your boat. They present this information as fish icons on the display unit to give anglers an idea of where to cast their nets for a fruitful catch.

Some of them come with a low-frequency transducer that can estimate the depth of the water column. This component comes in handy, especially when fishing in the deep sea.

5. Value

If you are searching for the most cost-effective option, a depth finder might be the best choice. Most depth finder options on the market are cost-effective, owing to the basic features these devices come with.

Although there are high-end depth finders, the functionality of each lies in the ability to read depth, which is the most crucial feature for a depth finder. Therefore, a more affordable option will work just right if you are on a tight budget.

If you have more to spare, go for an advanced finish finder; it comes with fish-finding features with the additional capability of reading water depth. That way, you will get the functionality of teo devices in one, especially if you use them on a regular basis.

Nevertheless, you have to factor in what purpose you want the device to serve. If you do not fish regularly, a depth fish finder will work just fine to help you read the water depth. But if you are always on the hunt for fish, a fish finder is the most essential tool to have.

6. Mounting Options

Most depth finders are portable and do not need any mounting. Some come in a flashlight design that can be handheld or hung around the neck with a neck strap. However, a few of them need to be mounted onto your boat.

On the other hand, most fish finders are mountable. They come with transom-mount, in-hull transducers, or through-hull transducers that must be installed on your boat.

The Bottom Line

Fishfinders and depth finders both use sonar technology to find fish. However, they are not the same. There are many unique differences between them. Hopefully, this article has shed more light on the differences and will help you decide which one to buy between the two.


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