How many sonar units (or “graphs”) do you really need in your boat? It’s one of the most common questions anglers ask, and the answer isn’t a one-size-fits-all situation. According to Angling Edge’s Mike Hehner, the right number of graphs depends entirely on how you fish, where you fish, and what species you’re targeting.
From simple tiller setups to multi-unit bass rigs, your sonar configuration should match your style, not just the latest trend. In this article, Mike walks us through the practical logic behind his three-graph boat layout, and we’ll break down when fewer (or more) screens might make sense for you.
Why the Number of Graphs Depends on How You Fish
Not every angler needs four screens running 24/7. A weekend walleye chaser on a Northwoods lake has very different needs than a bass pro running a national tournament trail. 
“If you’re a bass pro, you probably have four or five in your boat,” Mike explains. “But if you’re a weekend angler or have a boat up at the cabin, you might only need one.”
The number of graphs in your boat should be based on:
- The species you’re targeting
- How much time you spend fishing
- Whether you fish solo or with a partner
- How much you rely on different sonar technologies
- Your comfort level switching between screens
Mike Hehner’s Setup: A Smart 3-Unit System That Covers It All
Mike’s boat is equipped with three Humminbird Helix units, a setup that provides full sonar coverage while remaining clean, simple, and efficient.
Here’s how it’s laid out:
Rear Console:
- Helix 12
- Primary use: Mapping and Mega Live
- Also configured for split-screen if needed (Map + Live)
- Larger screen for easier viewing when navigating
- Helix 10
- Primary use: 2D Sonar and Side Imaging
- Used while scanning and moving between spots
Bow (Trolling Motor):
- Helix 10
- Used for Down Imaging, 2D Sonar, and Mapping
- Ideal for vertical presentations or spot casting from the front deck
This three-graph layout allows Mike to cover all major sonar modes:
- Mapping
- 2D sonar
- Side imaging
- Down imaging
- Mega Live
“I probably spend most of my time in the back of the boat by the tiller,” Mike explains, “but when I move to the bow, I’ve got another Helix 10 up there to stay dialed in.”
Why Use Different Graphs for Different Sonar Modes?
Each sonar technology has a specific use on the water. If you’re running a multi-graph setup, here’s how to think about each tool:
Mapping:
- Essential for navigating, waypoint marking, and finding contour changes
- Larger screens (like a Helix 12) are great for viewing detailed chart info while running
2D Sonar:
- Classic fish-finding tool that shows arches, bottom hardness, and bait
- Great for real-time depth and vertical fishing
Side Imaging:
- Crucial for locating structure, fish, and transition zones while moving
- Best used while driving slowly and scanning out to the sides
Down Imaging:
- Offers clearer structure details beneath the boat
- Useful for vertical jigging and drop-shotting
- Helps ID fish vs. weeds or rocks
Mega Live:
- Real-time sonar showing fish movement and lure response
- Ideal for active target-style fishing, especially in deeper water
By assigning these modes to different screens, Mike avoids constantly switching screens, meaning more time fishing and less time fiddling.
When a 1- or 2-Unit Setup Makes Sense
You don’t need three screens to catch fish. For many anglers, especially those running tiller boats, a single, versatile unit can go a long way.
1 Graph Setup:
- Ideal for small boats or casual anglers
- Use a screen like a Helix 7 or 9 with split view
- Combine 2D sonar and GPS mapping on one screen
- Add a transducer with Down Imaging or Side Imaging if possible
2 Graph Setup:
- Great for anglers who move between front and back decks
- Console unit for navigation and scanning
- Bow unit for vertical fishing and casting
This layout allows you to fish more efficiently without overloading your rig, especially on smaller boats or setups with limited battery capacity.
When 4 (or More) Screens Might Be Justified
Some anglers want maximum data at all times, and there’s nothing wrong with that if your fishing style demands it. Here’s when four (or more) graphs make sense:
- Dedicated Mega Live screen to avoid split viewing
- Full-size mapping unit with no shared view
- Side imaging on one screen, 2D sonar on another
- Bow rigging with both Down Imaging and Live sonar
This kind of setup is ideal for:
- Tournament anglers
- Guides who fish daily and need efficiency
- Serious tinkerers and electronics junkies
Just remember: more screens mean more power usage, more rigging, and more cost, so make sure you’ll use what you install.
Build Around Your Fishing Style
You don’t need five graphs to catch fish, but having the right setup for how you fish can dramatically improve your efficiency on the water.
“Everybody has their favorite screens they use,” Mike says, “and I have mine set up the way I like.”
The key takeaway is this:
Your sonar setup should serve your strategy, not the other way around.
Start with how you like to fish:
- Are you vertical jigging?
- Casting from the bow?
- Driving and scanning with side imaging?
- Watching fish react in real time?
Then build your graph layout to support that. Whether it’s one, two, or three screens, you’ll catch more fish when your electronics help you stay focused, efficient, and informed.
*The Humminbird HELIX units mentioned in this article have been replaced by the new Humminbird XPLORE units:
XPLORE 10 – https://amzn.to/46FQ8me
XPLORE 12 – https://amzn.to/4nUOXGQ
