Fish Finder Sonar Technology Explained (with recommendations)



fish finder sonar tech

Unlocking the Sonar Secrets

For many anglers, a fish finder is the ultimate underwater spy. It helps reveal the secrets of the deep and can guide them to hidden fish havens.

But with various fish finder sonar technologies available, deciphering which one reigns supreme can feel overwhelming. Fear not, fellow fishers! This cheeky (and rather brief) guide unveils the mysteries behind common sonar types. Read this and with your new found knowledge you should feel empowered enough to choose the right tool to find those fish.

We’re going to look at three types of sonar technology that you’ll find in your fishfinder.

  • Traditional Sonar
  • Chirp Sonar
  • SideVü and DownVü Sonar

Let’s dive right in, shall we?

Traditional Sonar: The OG Fish Finder

Imagine a sonic ping bouncing off underwater objects and returning to the transducer. That’s the essence of traditional sonar, the workhorse of the fish finder world. It provides a two-dimensional image directly below your boat, indicated by vertical lines (returns) on the screen. Stronger returns represent denser objects, potentially fish or bottom structures.


  • Simple to understand: Easy-to-read display perfect for beginners.
  • Excellent target depth: Ideal for deep water exploration.
  • Cost-effective: Generally the most affordable option.


  • Limited detail: Doesn’t provide information about objects to the side of the boat.
  • Interpretation required: Requires practice distinguishing fish from other underwater features.

Our favorite basic fish finder – Lucky Fish Finder

LUCKY Portable Fish Finder Transducer Sonar Sensor 147 Feet Water Depth Finder LCD Screen Echo Sounder Fishfinder with Fish Attractive Lamp for Ice Fishing Sea Fishing

We really like the Lucky Fish Finder for a couple of reasons besides the fact that it has a great name!

The LUCKY Portable Fish Finder offers a budget-friendly solution for anglers seeking a convenient way to locate fish and measure water depth. Here’s a quick rundown of its key benefits:

  • Portable & Easy to Use: The compact and lightweight design makes it ideal for kayak fishing, ice fishing, shore fishing, or any situation where portability is a priority.
  • Affordable Fish Finding: For budget-conscious anglers, the LUCKY Portable Fish Finder provides a cost-effective way to enhance their fishing experience.
  • Depth & Fish Detection: This fish finder displays water depth, helping you locate potential fishing spots. It also provides basic fish location icons, offering a general idea of where fish might be hiding.
  • Simple Operation: With user-friendly controls and a clear display, the LUCKY Portable Fish Finder is easy to set up and operate, even for beginners.

CHIRP Sonar: The All-Seeing Eye

CHIRP (Compressed High-Intensity Radiated Pulse) sonar takes traditional sonar a step further. It transmits a continuous “sweep” of frequencies instead of a single ping. This allows for clearer target identification and superior bottom detail, offering a more lifelike picture of the underwater world.


  • Superior target separation: Distinguishes fish from clutter and differentiates fish sizes.
  • Sharper bottom definition: Reveals bottom hardness and composition (rock, sand, etc.).
  • Improved performance in deep water: Maintains clarity at greater depths.


  • Higher cost: Generally more expensive than traditional sonar.
  • Steeper learning curve: Interpreting the CHIRP display might require practice.

Our Favorite Chirp Fishfinder – Garmin Striker 4

Garmin 010-01550-00 Striker 4 with Transducer, 3.5" GPS Fishfinder with Chirp

Garmin Striker 4: A Budget-Friendly CHIRP Fish Finder

Looking for a powerful and affordable fish finder with CHIRP sonar technology? Look no further than the Garmin Striker 4! This compact and user-friendly device offers excellent value for beginner and budget-conscious anglers seeking to upgrade their underwater exploration.

Key CHIRP Advantages of the Garmin Striker 4:

  • Clearer Target Separation: CHIRP sonar transmits a wider range of frequencies, providing crisper fish arches on the display. This helps you distinguish fish from bottom clutter and even differentiate between fish of different sizes.
  • Enhanced Bottom Detail: Unlike traditional sonar, CHIRP offers a more detailed picture of the underwater world. You can identify bottom hardness (rock, sand) and locate structures that might attract fish.
  • Improved Performance in Various Depths: Whether you’re fishing shallow flats or venturing into deeper waters, CHIRP sonar delivers consistent clarity, helping you stay on top of fish activity.

Garmin Striker 4 Summary:

The Garmin Striker 4 is a compelling choice for anglers seeking a CHIRP fish finder without breaking the bank. Its CHIRP technology provides superior target separation, clear bottom detail, and reliable performance across depths, making it a valuable tool for fishing success.

Get some more information on the Garmin Striker 4 here.

fish finder sonar technology

SideVü and DownVü Sonar: Seeing What’s on the Sides

Imagine having underwater x-ray vision! SideVü and DownVü sonars achieve this by transmitting sonar signals sideways or downwards, respectively. This creates a detailed picture of what lies to the sides and beneath your boat, perfect for pinpointing fish hugging structures, submerged vegetation, or even drop-offs.


  • Unparalleled underwater visibility: Reveals structures and fish locations on the sides and bottom.
  • Ideal for shallow water: Excellent for exploring lakes, rivers, and near-shore areas.
  • Finding hidden fish: Spots fish holding tight to structures or following bottom contours.


  • Limited range: Generally has a shorter scanning range compared to traditional sonar.
  • Increased cost: Typically requires a separate SideVü/DownVü transducer (more expensive).

Our Favorite SideVü and DownVü Sonar Fish finder – Lowrance HDS Pro

Lowrance HDS PRO 9 Inch Fish Finder with ActiveImaging HD 3-in-1 Transducer with Smartphone Integration

This is a serious bit of kit.

The Lowrance HDS Pro series isn’t just a fish finder; it’s a complete fishing command center. For serious anglers seeking the pinnacle of sonar technology and integrated fishing tools, the HDS Pro stands out as a top contender.

Here’s a deep dive into its features, exploring what sets it apart from the competition:

Unmatched Sonar Prowess:

  • Dominating SideVü & DownVü Clarity: The HDS Pro boasts industry-leading SideVü and DownVü sonar, offering photorealistic images of underwater structures and fish locations up to 600 feet (183 meters) to the sides and 300 feet (91 meters) below. This allows you to pinpoint fish hugging structures, identify submerged vegetation, and visualize bottom composition with unparalleled detail.
  • Game-Changing ActiveTarget Technology: Take your fish finding to the next level with optional ActiveTarget live sonar. This innovative technology provides real-time, high-resolution moving images of fish and structures in front of, below, and around your boat. Witness fish behavior in stunning detail, allowing you to react strategically and maximize your catch rate.

Lowrance HDS PRO 16 Inch Fish Finder with ActiveImaging HD 3-in-1 Transducer with Smartphone Integration

Advanced Features for the Discerning Angler:

  • High-Definition Display Options: Choose from 9-inch, 10-inch, or 12-inch SolarMAX HD multi-touch displays, offering excellent visibility even through polarized lenses. Enjoy vibrant colors, sharp details, and a responsive touch interface for intuitive control.
  • Expanded Charting & Networking Capabilities: HDS Pro integrates seamlessly with C-MAP DISCOVER Onboard charts, featuring high-resolution bathymetry with 1-foot contours for over 19,000 lakes in the US and 9,400 in Canada. Plus, network your HDS Pro with other onboard electronics like trolling motors and radars for a fully integrated fishing system.
  • Enhanced Trolling Motor Control: Enjoy effortless control of your Ghost trolling motor directly from the HDS Pro. Utilize new features like Anchor at a Distance and Orbit around a waypoint for ultimate precision fishing.

Standing Out from the Crowd:

Compared to other high-end fish finders, the HDS Pro offers several key advantages:

  • Unrivaled SideVü & DownVü Performance: The clarity and range of its SideVü and DownVü sonar surpass many competitors, providing unmatched underwater visibility.
  • ActiveTarget Live Sonar Advantage: The optional ActiveTarget technology offers real-time moving images, a feature not commonly found in most fish finders. This provides a significant edge in understanding fish behavior and making informed fishing decisions.
  • Integrated Fishing System Potential: With its networking capabilities, the HDS Pro allows you to create a centralized hub for controlling various fishing equipment, streamlining your fishing experience.

Things to Consider:

  • Price: The HDS Pro is a high-end fish finder with a price tag to match. Carefully evaluate your needs and budget before investing.
  • Learning Curve: With its extensive features, the HDS Pro may have a steeper learning curve compared to simpler fish finders.

Overall, the Lowrance HDS Pro fish finder is a powerful tool for serious anglers seeking the best possible sonar technology, advanced features, and the potential for a fully integrated fishing system. While the cost might be a barrier for some, the unmatched sonar performance, innovative features, and long-term value proposition make it a compelling choice for those who demand the ultimate on-the-water experience.

You can read some more on the Lowrance HDS Pro fish finder here.

Choosing the Right Fish Finder Sonar

In order to pick the right sonar for you and your budget, consider the following final points:

  • Deep Water Dominator: For deep water exploration and targeting bottom fish, traditional or CHIRP sonar excels.
  • Shallow Water Specialist: SideVü and DownVü shine in shallow water, revealing structures and fish near the bottom or sides.
  • Ultimate Versatility: If budget allows, CHIRP combined with SideVü/DownVü offers the most comprehensive underwater picture.

Remember: The best sonar technology depends on your fishing style and target species. Consider factors like water depth, your desired information, and budget when making your choice.

If none of the above fish finders tickle your fancy, then make sure to check out our Garmin Striker Vivid 9sv review here.

Hopefully, with this knowledge, you’ll be able to use these sonar fish finders to catch your dinner!

Happy fishing!

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