There is nothing like the feeling of landing that prize fish. At ePal, we understand the complexity of buying a fishfinder; our buyer’s guide offers insight on how fishfinders work and what features to look for when purchasing one.
First let’s talk about what a fishfinder does and how it works. Fishfinders, also called depth finders, are tools that fishermen use to see what is under their boat. In order for a fishfinder to work, you must hook it up to a transducer. The transducer is the instrument that sends out sound waves which reflect off objects under your boat. Such objects include fish, the ground, vegetation, logs, rocks, and shipwrecks. The sound wave produces a signal that is sent back to the transducer which allows you see the objects represented on the screen. You can start to see why having a fishfinder onboard can greatly improve your odds of landing that prize fish. Now that we know how they work, let’s get into more specific details about what to look for in a fishfinder. I’m sure you’ve seen models that range in price from as low as $50 to an upwards of thousands of dollars. There are two key factors that make some pricier than others: the screen and type of transducer.
First, let’s take a look at transducers. As I mentioned above, this is the instrument that sends and receives the sound waves. When purchasing one, the first question we need to ask is what kind of material should I get? There are 2 popular types of materials:
1. Plastic housings: Plastic is usually more cost effective and recommended for metal and fiberglass hulls.
2. Bronze housing: These are usually pricier and recommended for wood and fiberglass hulls. As you know, wood can expand and cause damage to a plastic housing which could cause a leak.
The next question to answer is how should I mount the transducer? There are 4 different mounting options:
1. Transom mount: With this option, you would mount the transducer at the boats transom so it is directly in the water. These transducers are usually more cost friendly and pretty easy to install.
2. In-Hull (or shoot-through): This kind of transducer is usually only used with fiberglass hulls and would be epoxied directly to the inside of your hull. Because the signal is transmitted through the hull of your boat, it will not be as strong as the other 3 methods. With this option, you would have a reduced depth reading and fish detection. There are, however, some plus sides to this though. First, you do not have to drill any holes in the hull of your boat and second it is very low maintenance.
3. Through-Hull: There are 2 different kinds of through-hull transducer but we will look at the standard one first. With this kind of mount you would drill a hole in your hull and the transducer would protrude directly in the water. Through-hulls are recommended for displacement hulls and boats with straight-shaft inboard engines. They usually also come with a fairing block that allows for proper installation. Because of the way the transducer is installed, through-hull provides the best performance.
4. Tilted Element: This is the second kind of through-hull transducer. With this kind of mount you would also drill a hole in the bottom of your boat but unlike the standard through-hull you do not need a fairing block. This kind of transducer would mount flush against the hull and the element in the transducer acts as a leveling agent with the deadrise (or angle) of your hull.
Finally, let’s talk about power and frequency. Power is rated by watts RMS. The more powerful the sonar is, the deeper it can read and the clearer the readings will be. Just as an example, a 100 watt sonar can go to a depth of about 600 feet while a 500 watt sonar can get to about 1500 feet.
Frequency and cone width are your last transducer decision. Luckily for you, the manufactures usually pair the fishfinder with what they believe will be the best transducer for the job. So let’s look at a common transducer, the dual frequency 50/200KHz. This kind of transducer is normally used for salt water. Since water absorbs sound waves at a slower rate for lower frequencies, the 50KHz is used for deep readings and the 200KHz is used for shallower water, mostly up to 200 feet. It is important to remember that lower frequencies have a wider cone which also means that you get less target definition. Higher frequencies have a narrower cone but return much better detail and can detect smaller objects.
Next deciding factor is the display. This is where you will see the information the transducer receives. There are 3 main decisions you will need to make here:
1. Do you want a color screen?
The question is, do you choose color or monochrome. If you are on a budget, your best option is the monochrome or grayscale display. Grayscale displays are easy to read in the sunlight and can be purchased at a low price. Moving to a full color display will obviously give you more detail, allowing fish and structures to show up in different hues. Click here to view all of our color fishfinders. Click here for the Monochrome Fishfinders.
2. What resolution do you want?
Like any LCD screens now days, the detail comes with the amount of pixels you have on the screen. The more pixels you have packed on the screen the more realistic the image looks (think normal TV to an HDTV). A good example to look at would be the Garmin Echo 500C vs. the Garmin Echo 550C. They both have a 5 inch screen but the 500C has a 234 x 320 pixels resolution while the 550C is at 480 x 640 pixels.
3. What screen size do you want?
Last and certainly not least is screen size. A lot of factors play a role here so I hate to give advice without personally talking to my customers so I’ll just leave you with this: get the size that you will enjoy looking at, at the price you can afford. Something you many want to ask yourself before purchasing a fishfinder is if you want the ability to use a GPS on the same screen. This would allow you to purchase maps and save hotspots so you can easily find your way back to great locations. I will be doing a buyer’s guide for that in the future so look out for it!
There is one more thing I want to talk about before I end this buyer’s guide and that is some of the cool new technology available now. Both Lowrance and Humminbird have great new imaging setups. Lowrance calls theirs DSI and Structurescan and Humminbird calls theirs Down Imaging and 360 Imaging. Instead of the sonar images we are used to seeing on the screen these technologies give you a photo like view of what is under the boat. I would highly suggest getting a fishfinder with one of these technologies!
Thank you for taking the time to read this. If you have any questions about fishfinders please do not hesitate to give us a call or use the chat function at the bottom of your screen!