Buying Guide

How to Choose a Fish Finder?

Choose a Fish Finder

Device called a fish finder is remarkably effective and reliable equipment. It will enable you to identify fish and also it will help you to portrait how the bottom of the lake/water is structured and other stuff that you could never imagine were beneath you. You should have in mind though, that you need to carefully investigate and review the best device out there and choose the best fish finder that fits your personal needs. This is because if you make a mistake in the process of buying your own fish finder, it can cause your device to become ineffective and useless.

Basically, a fish finder will provide you with a graphic image of what is under your boat, may it be fish or the structure of the bottom. In other words it will help you to identify fish. To make sure you choose the best fish finder, you need to keep in mind what kind of unit it is that you are about to purchase. Does it include GPS? Do I need a big or a small sized fish finder? How is the resolution of the display? How much transmitting power do I need? What frequencies will work best in my area? Am I going to use it in shallow water or deep water environment?

It is so easy to get lost in all the technical analysis and looking for information about fish finders, such as investigating echoes, sonar, transducers, mounts, flashers and so on. However the most important question of all questions that you will ever ask yourself is: Will this particular fish finder really help me to catch the most fish? Those are all great points and questions and that is the main reason why I put together this fishing guide. The main objective here is to help you to make the best decision when you decide to invest in a fish finder and hopefully after reading this guide you will have all the answer you need.

Power of the fish-finder

One of the crucial elements to think about prior to investing in a fish finder is power. The power is always calculated in watts (labeled W). The more wattage you have, then your device will work faster to portray the information on the screen from beneath. Also, the more wattage, the better your analysis can be. If you have less wattage then your fish device will be slower in operation. The lesser wattage is more suitable to use in shallow water. Basically, if you have less power, then the sonars waves are going to be significantly slower travelling and the information projected on your display might be fuzzier. On the other hand, with more power (more wattage) then the fish finder will operate faster and will display the information much clearer.

You need to keep in mind few things regarding the power. Basically, your finder will show readings up to 400 feet at 50 kHz for every 100(w). It will show information up to 100 feet at 200 KHz for every 100W of power. In order to get information from both frequencies (50 & 200) you should look for dual-frequency fish finder. They are usually marked as 50 / 200 or 85 / 200 (most, if not all mid-range finders are dual).In summary, for shallow water you need less power. If you want to fish in deep water then you should go for the most powerful fish finder, i.e more wattage.


Just like the power, the quantity of the pixels on the screen is extremely important element to think about. In short, a pixel is just a small dot showing on your display. This dot represents the tiniest |magnitude of details that your display screen is able to show you. When you have billions of these small dots all together on the screen it is actually what represents the whole image of what you see on the screen. For example, let’s say your screen is 860×860 pixels. Basically, what this means is there are 860 dots in each row right to left, also 860 dots on the vertical scale(from up-down).

In essence, the more pixels that your device has, the more details you will see. If you are out there looking for crystal clear and crisp image, it might be good idea to invest in a high resolution display screen. The size of your screen also is another thing to keep in mind because screen resolution (pixels) along with the size of the screen on your device will determine how clear image your device has. Obviously, with the cheap fish finders you will notice they include smaller display screens. It doesn’t mean it is a bad choice but it should more be considered as a backup fish finder though. If you can afford, you should try to invest in the biggest screen that your wallet will allow. It will be a good investment for future. It will provide you all the information you need in a greater details.

What to know about frequencies

Again, just like the power and screen resolution, the frequencies are extremely important factor in transducers. If it’s a dual frequency transducer, it will include 20 & 60 degree cones. Almost all transducers will be available in 50, 83, 192 or 200 kHz depending on the cone angle. Let me explain the different frequencies briefly: High frequencies such as 192 or 200 kHz are going to be ideal to operate in shallow water. On the other hand, low frequencies like 50 kHz will be idea to use in deep water and is more thought of for professionals.

Keep in mind that if you use higher frequency you will have more details on your display screen because of the quantity (so many) of sonar waves being transmitted and obtained from the transducer. Therefore, for shallow water, this is ideal. There are even available out there fish finders that are over 400 kHz and not only dual frequency but multiple! This will provide you with extremely in-depth detail graphics, but you can of course easily switch to more general and broader views.


This is the main part that transmits and obtains sonar waves. How do they work? Basically, what they do is to transmit sonar waves deep down the water and when they hit the objects on the way, or reach the bottom they bounce back and the transducer picks up the wave. Then it takes the information that it received and converts it into an image for you to understand and see better.

Transducer Materials

Despite the fact that transducers can be produced in all kinds of materials, almost all the fish-finder models include plastic-type mount transducers in the package. This is absolutely fine for the majority of casual-fisherman and it installs easily on all sorts of boats, apart from probably a flattish boat that relies on pontoons to float where you might need to be a little creative to attach the transducer and might consider another place to install.

If you have an in-hull transducer with plastic-type protective covering or housing are generally appropriate for hulls contain metal. Steel (preferably stainless steel) housings will be ideal for metallic or aluminium hulls. Bronzy housings are best for fibreglass or timber hulls. If you choose/prefer wooden hulls, you should consider using bronze and not plastic simply because if the wood expands it could damage your plastic transducer so you will most definitely end up with a leak. Please be aware that you should not install a transducer with metal housing in case your boat contains positive ground feature.

There are more extra features that you can have, for example small unit to show temperature that will aid you to locate the perfect temperature for the fish you are trying. Another feature is, for example, distance and speed attribute. This will give you information about your current speed at the time the fish caught your bait.

Color or black&white Screens

Nowadays, color is the new trend in all electronics. Why? Because color will offer you far better detail and provide you with billions of colors compared to a b&w screen. Color screen will assist you greatly to understand what is going on beneath you as it would make all objects down there clearly show up on your screen. Also the efficiency of the screen will depend on the weather and the environment around you.

You will find it much easier to glance on a color screen in bright light than black and white screen or if it’s cloudy the color will be much clearer than b&w. In other words, your fishing experience will be a lot better if you invest in a color screen. You can still go for b&w screen but it won’t be as joyful. If you don’t have the budget for color screen, I suggest you wait until you can afford one instead of going for b&w. It might seem a good place to start but the reality is that long term, it just won’t be worth it!

Cone angle

Yet another crucial factor is the cone angle. To explain what a cone-angle is briefly, you can think of it as some sort of a beam that is transmitted from your boat and down into the water in a cone shape. Starting from the bottom of your boat, it goes wider and wider as further down it gets. The more deeper you go, the wider the cone and larger area is covered. It is essential to bear in mind that in deep water as the cone gets wider, you will lose the signal in very deep water.

You can buy transducer from 9 degrees to over 60 degrees. The popular devices are often times from 16 degrees to 20 degrees and should be ideal starting point for those of you guys that prefer to fish in different water (both deep and shallow water). If you want to be able to cover even more water and as you get more advanced, you could get a dual beam or even triple beam because each one of extra beam will aid you to cover more water.