Fish finders are like opinions…everyone’s got one. Considered as important than beer, fish finders aim to be your boat’s secret eyes and ears in the water. But are they really worth it?
Well, it depends on you.
Here’s what you need to know to make your fish finder into a fish-hunting predator!

El Cheapo
Simply, all fish finders are NOT created equal.
Price definitely indicates quality. And you certainly get what you pay.
You definitely need to consider the features you’ll need for your kind of fishing — not just $$$. Going the el cheapo route without thinking about your kind of fishing is a sure way to sink success. So, before buying, you need to consider the type of fishing you’ll do.
Overkill
Here’s the opposite extreme — expensive bells and whistles, but no idea how to operate them!
Costlier units always require a lot more time to master. Having the time and patience to read the manual is required if you go this route. If you’re not a tech geek nor have the time, then expensive units might not be your best bet.
Fishing needs always dictate functionality. Remember, you might be happier with less features in a slightly cheaper unit than something more expensive, packed with features you don’t need.
Golden Oldie
If you spoke to the Disciples, they’d tell you — “Thou shall not hold onto thy old fish finders.”
Old units can not only make mistakes, but depending on how old, could really only be elementary compared to today’s latest technology. Technology has about a five-year cycle. What was top-of-the-line just five years ago, is basically bare-bones-basic today. If it’s already 5+ years old, then it’s time to give Davy Jones your unit.
The Installation and Functionality
Your fish finder is only as good as it’s installed and optimised. Being careless during installation always proceeds being useless later.
Here are some common mistakes to avoid during installation:
- The transducer is too close to a turbulence causing structure.
- The transducer isn’t position correctly just below the water line, just under the hull.
- Wiring sits too close to other electrical interference.
- The extra transducer wire is coiled wrong.
- The transducer doesn’t sit level up.
Even if your fish finder was professionally installed, it’s always a good idea to double check your equipment. It’s your time on the water, not theirs!
Also, during installation don’t just accept default settings. Here are some key settings to check:
- Select the correct transducer
- Select the type of fishing you’ll be doing
- Turn off any “Fish ID” functionality — very unreliable.
- Increase scroll speed and sensitivity
- Choose a good contrasting color
- Set the frequency/CHIRP mode — many prefer a lower frequency for a wider cone area.
So, now we know some pitfalls, it’s time to make your finder into effective eyes and ears beneath the waves.

Wielding Your Finder…
It’s not rocket science, but understanding the below basic concepts will immeasurably increase what you get out of your unit.
Basic Concepts
Fish finders consist of two main parts — the transducer and the head unit. The transducer produces an underwater sound wave which bounces off objects and returns. Based on time and density of the object found in returning signals, the results are displayed on the finder screen in depth and hardness in colour.
As the sound waves travel down, they spread out to form a sonar-cone shape. If your unit, say, has only a 20-degree cone, then you’re going to be viewing a shorter radius of objects. If the sonar cone radius is larger, say 35 degrees, then you’ll be able to capture a larger range of objects.
The frequency of the transducer directly affects the final radius of the sonar cone. Normal sonar usually operates between 50kHz to 200kHz. The lower the frequency, the wider the cone and deeper area you will be able to see. But what you gain in area and depth, you also lose in resolution. The opposite is true for higher frequencies, which get you a much better resolution but at shallower depth and smaller final radius of seen objects.
Other Kinds of Sonar
Other types of sonar include downscan, CHIRP and side-scan sonar. Each have different benefits.
Downscan is a high-frequency sonar which can easily distinguish between underwater structures and fish you want to catch. Highly useful when you know where certain kinds of fish hide!

Buying the Perfect Unit
Here are some key pointers for anyone about to buy a new fish finder:
- Get at least a 7-inch screen
- Get down-scan, CHIRP and side -can sonar
- Freshwater transducer 83-200kHz for shallower waters, and saltwater transducers if you fish in 200ft or more depth.
- Built in GPS — very helpful to repeat exact locations where you snagged the last one.
- On-the-fly mapping — ability to create instant contour maps to know the exact layout below!
On average, you’ll pay between $600-$900 for these features.
Here are some great suggested units in this article.
Whew! A fish finder — like anything in life — is what you make of it. Just because you’ve got one, doesn’t mean it’s going to work!
Knowing the pitfalls, the basics how they work, grasping functional differences, properly installing units and tailoring the settings will greatly impact the usefulness of your fish finder. So, be picky, know your needs and act on them. If you do, some great fishing days are bound to be on your horizon!