How to Use a Fish Finder for Fall Fishing | Essenbay Marine

Kyle Essenmacher

Find More Fish This Fall: How to Get More From Your Fish Finder

Your fish finder can tell you the depth.

It can show you the bottom.

It can help you navigate.

But if that's all you're using it for, you're leaving one of the most useful fishing tools on your boat largely untapped.

That's especially true during fall.

As we discussed in Part 2 of our Fall Fishing Series, changing water temperatures and seasonal conditions can alter where bait and gamefish are located. The productive water you found during summer isn't guaranteed to stay productive.

Instead of guessing where the fish moved, your electronics can help you search for them.

In Part 3 of the Essenbay Marine Fall Fishing Series, we're breaking down how to use sonar, imaging, mapping, and a few basic fish-finder adjustments to spend less time fishing empty water and more time around fish.

First: Stop Thinking of It as Just a Fish Finder

The name can actually be a little misleading.

Your electronics aren't valuable only when they draw a fish-shaped return on the screen.

They're giving you information about the underwater environment.

A modern sonar/GPS system can potentially help you understand:

  • Water depth
  • Bottom contour
  • Changes in bottom composition
  • Submerged vegetation
  • Brush and timber
  • Rock and other hard structure
  • Drop-offs and ledges
  • Baitfish
  • Individual fish
  • Water temperature
  • Your location relative to productive structure

When you start combining those pieces of information, your fish finder becomes much more than a screen showing what's underneath the boat.

It becomes a tool for developing a fishing pattern.

1. Start With the Map Before You Start With Sonar

One of the most efficient ways to find fish is to narrow down the amount of water you need to search.

That's where GPS mapping comes in.

Before you begin scanning randomly, use your chart to identify areas that have the potential to hold fish.

Depending on the body of water, that might include:

  • Points
  • Creek channels
  • Channel swings
  • Ledges
  • Drop-offs
  • Humps
  • Flats adjacent to deeper water
  • Reefs
  • Inlets
  • Creek mouths

You're not saying, "There are definitely fish here."

You're saying, "This area gives me a reason to investigate."

That's an important distinction.

Mapping finds the potential spot. Sonar helps you decide whether it's worth fishing.

2. Learn What Bait Looks Like

During fall, finding forage can be every bit as important as finding individual gamefish.

Baitfish can appear differently depending on the sonar technology, settings, depth, and how tightly the bait is grouped.

Rather than looking for a perfect textbook image, start learning what concentrations of bait look like on your electronics.

You may see:

  • Dense clouds or clusters
  • Smaller scattered returns
  • Bait positioned close to the bottom
  • Suspended concentrations
  • Predator returns positioned near or underneath bait

When you find significant bait activity, pay attention.

Even if you don't immediately see obvious larger fish around it, you've found one of the ingredients that can make an area productive.

3. Understand Traditional Sonar

Traditional 2D sonar remains incredibly useful.

It gives you a continuously updating view of what's passing through the sonar cone beneath your transducer.

Depending on your equipment and settings, stronger returns may appear differently than weaker ones, and fish can sometimes display as arches or partial arches.

But don't become obsessed with finding perfect arches.

Boat speed, fish movement, transducer position, cone angle, and other factors can change how returns appear.

Instead, focus on learning the relationship between:

  • Bottom
  • Structure
  • Bait
  • Larger returns

The more time you spend comparing what you see on-screen with what you catch, the more useful sonar becomes.

4. What Does CHIRP Do?

Many modern fish finders use CHIRP sonar.

Instead of transmitting at only one fixed frequency, CHIRP systems can transmit across a range of frequencies.

In practical fishing terms, compatible CHIRP systems can provide improved target separation and detail compared with traditional single-frequency sonar.

That can help when you're trying to distinguish individual targets near bait, structure, or the bottom.

You don't necessarily need to understand every piece of sonar engineering to benefit from it.

The important part is knowing what technology your fish finder and transducer support—and making sure they're configured correctly.

5. Use Down Imaging to Investigate What's Below You

Down imaging technologies from different manufacturers are designed to provide a more picture-like representation of structure beneath the boat.

This can be particularly helpful when traditional sonar shows something interesting but you're not quite sure what you're looking at.

For example, down imaging may help you better distinguish:

  • Brush
  • Standing timber
  • Rock
  • Vegetation
  • Bait
  • Fish near structure

Think of traditional sonar and down imaging as complementary tools rather than competitors.

Running them together can provide additional context.

6. Side Imaging Can Help You Search More Water

This is where electronics can completely change the way you search.

Traditional sonar primarily tells you what's happening beneath the transducer.

Compatible side-imaging systems allow you to look outward to either side of the boat.

That means you can search a much broader area without driving directly over every piece of structure.

Depending on conditions and your equipment, side imaging can be useful for locating:

  • Rock piles
  • Brush
  • Timber
  • Drop-offs
  • Bottom transitions
  • Submerged objects
  • Fish away from the boat

When you find something interesting, mark a waypoint.

Then circle back and investigate it more closely.

Scan first. Fish second.

That mindset can save a tremendous amount of time.

7. Don't Leave Your Fish Finder on Settings You Don't Understand

Modern electronics can be intimidating.

Sensitivity. Gain. Frequency. Range. Contrast. Color palettes. Noise rejection. Scroll speed.

It's tempting to leave everything alone forever.

Fortunately, automatic settings on modern units can provide a good starting point for many anglers.

But over time, learning a few basic adjustments can make the display much more useful.

Start with these:

Sensitivity or Gain

This generally controls how much sonar information appears on the display.

Too little sensitivity can hide useful returns.

Too much can fill the screen with clutter.

The goal isn't necessarily the cleanest-looking screen. It's a screen that shows useful information without overwhelming you with noise.

Depth Range

Automatic depth range is convenient, but manually narrowing the displayed range can sometimes make it easier to focus on the portion of the water column you're actually fishing.

Frequency

If your transducer supports multiple frequencies, different settings may be useful for different depths, coverage areas, and levels of detail.

Check the recommendations for your specific manufacturer and transducer rather than assuming one frequency is always best.

8. Use Waypoints for More Than Your Favorite Fishing Holes

A waypoint shouldn't only mean:

"I caught a big fish here once."

Use waypoints to record useful underwater information.

Mark:

  • Brush piles
  • Rock
  • Edges of vegetation
  • Drop-offs
  • Productive stretches
  • Bait concentrations
  • Underwater transitions
  • Navigation hazards

Over time, you're building your own map of how you understand the body of water.

That information becomes especially useful during seasonal transitions because you can revisit different types of structure as conditions change.

9. Pay Attention to What Happens After You Catch a Fish

This is one of the simplest habits you can develop.

When you catch a fish, look at the electronics.

What depth are you in?

What depth was the fish?

Was there bait nearby?

What does the bottom look like?

Are you near a drop-off?

Vegetation?

Rock?

A creek channel?

What is the water temperature?

What direction is the wind or current moving?

The fish you just caught is giving you information.

Your electronics can help you understand what that information means.

If you catch several fish associated with similar conditions, you've potentially identified a repeatable pattern.

10. Don't Spend the Entire Day Staring at the Screen

There's a funny thing about modern fishing electronics.

They're so capable that it's possible to become more interested in the screen than the water.

Electronics are a tool.

Use them to narrow down productive areas, understand structure, locate forage, and make informed decisions.

Then fish.

Watch for birds.

Look for surface activity.

Notice current seams.

Observe where bait is moving.

Pay attention to wind.

Some of the best information available to you isn't digital.

Fish Finder Mistakes That Waste Time

Before your next trip, avoid these common habits:

  • Fishing every mark: Not every return on the screen needs a lure dropped onto it.
  • Ignoring bait: Forage can be more important than seeing individual gamefish.
  • Never adjusting settings: Automatic modes are useful, but learn what the basic controls do.
  • Driving too fast while scanning: Different sonar technologies perform best under different conditions and speeds.
  • Never marking waypoints: Interesting structure is much harder to revisit if you don't save it.
  • Assuming every screen image is obvious: Sonar interpretation takes practice.
  • Fishing yesterday's spot instead of today's conditions: This is especially important during seasonal transitions.

Considering a Fish Finder Upgrade?

If your current electronics don't offer the mapping, sonar, or imaging capabilities you want, fall can be a good time to evaluate your setup.

When comparing fish finders, consider:

  • Display size
  • GPS and mapping capabilities
  • CHIRP support
  • Side-imaging capability
  • Down-imaging capability
  • Included transducer
  • Networking compatibility
  • Available mounting space
  • Freshwater vs. saltwater use
  • Other electronics already installed aboard your boat

Don't shop based solely on screen size or price.

Start with the fishing you actually do and choose electronics that support it.

You can browse GPS and fish finder combos at Essenbay Marine or read our guide to the best fish finders for inshore fishing for more information.

🎣 The Essenbay Marine Fall Fishing Series

Part 1: The Fall Fishing Playbook: How to Get Your Boat Ready for the Best Fishing of the Year

Part 2: Where Did the Fish Go? How Cooling Water Changes Fall Fishing

Part 3: Find More Fish This Fall: How to Get More From Your Fish Finder ← You Are Here

Coming Next — Part 4: Boat Positioning Is Everything: Trolling Motor Strategies for Fall Fishing

Part 5: Fall Fishing Boat Setup: 10 Things You'll Be Glad You Have Onboard

Part 6: Freshwater vs. Saltwater Fall Fishing: How Your Strategy Should Change

Find the Pattern Before You Make the Cast

A fish finder won't catch the fish for you.

What it can do is help eliminate water.

Use mapping to identify promising areas. Use sonar to look for bait and fish. Use imaging to understand structure. Mark what you find. Then combine that information with the bites you get throughout the day.

The more you understand what your electronics are showing you, the less time you have to spend wondering where the fish went.

And once you've found them, there's another challenge:

Keeping your boat in the right position to catch them.

That's exactly where we're headed in Part 4 of the Essenbay Marine Fall Fishing Series: Boat Positioning Is Everything — Trolling Motor Strategies for Fall Fishing.

Ready to upgrade your fishing setup? Visit Essenbay Marine for marine electronics, trolling motor equipment, hardware, pumps, replacement parts, and boating accessories.

Veteran Owned & Family Operated.