How Does a Fishfinder, Chartplotter, GPS Combo Work?

Fishfinder, Chartplotter Combo
Fishfinder, Chartplotter Combo

Fishfinder, Chartplotter, GPS Combo Introduction

My Fishfinder combo works with they key technology that helps me plan new kayak and bass boat routes in lakes all over the U.S. and Canada. I also use it to track paths that I have stumbled on as I wander about the Georgian Bay in my Tracker.

Avid fisherman and boaters find many uses for this unit with navigation capabilities. It’s important, however, to get the right one. How do you do that? The key is to consider what the system does, how it works, how you plan to use it, where you plan to use it, and how much money you have to spend.

So What is a GPS,Fish Finder Chartplotter?

Some boaters and fishermen will use the terms as though they are synonymous. While the two are closely related, they are not the same. Essentially a Chartplotter with Global Positioning System (GPS) is a navigation system enabled Chartplotter.

A Global Positioning System device only determines your latitude and longitude coordinates and presents them as a numerical reading. For example, if you were docked at the Sans Souci Marina on Georgian Bay’s Frying Pan Island, your coordinates would be 45.1679° N, 80.1348° W. While these coordinates are helpful if you know how to use a paper chart, they are not particularly easy to envision.

That’s when a chart plotter comes in handy because it takes the latitude and longitude coordinates and plots it on a digital map. According to Garmin it’s essentially a piece of equipment that allows you to understand the results of the Global Positioning System computer.

This electronic navigation system takes the coordinates that you receive from your Global Positioning System receiver and shows them on an electronic map display. This allows you, boaters and fishermen, to constantly monitor your movement in relation to shorelines, shoals, sandbars, and other structures along your course above and below the water. This tool can determine the location of your craft and can use satellite information to track your speed and direction in real-time so that you know where you are on the map and where you are heading.

How Does the Global Positioning System (GPS) Work?

The Global Positioning System is a United States government system that uses satellite signals to determine the location of any GPS device. According to NASA, the Global Positioning System has approximately 30 satellites which are constantly sending out signals. According to, at any given time, you are visible to at least four of those satellites.

Global Positioning System receivers in phones, Chartplotters, or other devices pick up these signals, and, based on how much time it takes for the signal to travel from the satellite to your device, the device can tell where you are positioned. In the United States and Canada, the system also uses ground stations, known as the Wide Area Augmentation System or WAAS, to check that the satellites are actually where we think that they are located in space.

For a more in-depth explanation of how the Global Position System works, please see sciBRIGHT’s video on the subject.

How Does a Chartplotter WorK?

A Chartplotter is primarily used as navigation tools. If you have ever used Google Maps, you have essentially used a Chartplotter. The difference is that the kind of tool I am talking about here is for marine navigation.

This plotter takes latitude and longitude coordinates determined by a navigation or location system and plot them on a map or chart.

Some systems use Raster Charts, which are pictures of paper charts. The coordinates are then superimposed on the image of the paper chart in order to display location. The disadvantage of the Raster Chart systems is that they can be less accurate depending on the clarity of the paper chart image. They also take require a lot of storage space.

Other plotters use Vector Charts, which are replicas of paper charts that are created on a computer using database information. Vector Charts tend to be more accurate because the computer processor on the chart plotter does not have to store as much information. Vector charts also have three-dimensional capabilities, such as water depth, that Raster Charts do not.

A Chartplotter is made up of a database of charts or nautical maps. The processor in the tool takes the latitude and longitude coordinates and, using mathematical algorithms, shows you where those plot points are located on the graphic image of a map.

Fishing at Dawn
Fishing at Dawn

The Benefits of a GPS Fishfinder:

This navigation system can be an asset to boaters and fishermen. Many of the Global Positioning System device’s benefits follow. –Global Positioning Systems (GPS) are quite precise. They will usually allow you to pinpoint your location within four to five meters. Knowing where you are is essential when using paper charts to navigate or plot a trip over large bodies of water.

These systems are known to be speedy and generally accurate. The satellite information travels quickly to your device and gives you an almost exact read on your location.

GPS improves the safety of boaters and fishermen on the waters. Knowing your precise location is necessary for the event that you need help. A Global Positioning System reading will allow search and rescue operations to locate you quickly. It can also allow you to communicate your position to other boaters.

The Benefits of a GPS Chartplotter:

Since all Chartplotter systems use some kind of navigation signal, they have the benefits of the Global Positioning System. However, they also have additional benefits.

-These units allow you to record your route for future reference. Whether you are presetting a route to a new fishing spot or trying to retrace the steps that you took earlier in the day, these plotter systems can help you by allowing you to store your route.

-They are also great for allowing you to see your entire route at once. This tool can show you your estimated time of arrival and the distance between your current location and your destination.

-One of the most important benefits of these systems is that they can help you see what is below the water, which helps you to avoid obstacles such as reefs, sandbars, and shoals. Avoiding these underwater structures can make your boating and fishing experience much more pleasant

-These units allow you to store multiple waypoints. If you are fishing many species of fish on one trip, you will be stopping at many locations looking for the structure or cover particular to each fish. The chart plotter will allow you to mark those waypoints so that you can move from one to another seamlessly.

Which Fishfinder Combo Works Best?

Essentially, these plotter units use some type of navigation system. In the United States and Canada, most use the Global Positioning System. Therefore, a combination of a Chart plotter with the Global Positioning System is usually the best solution. A navigation enabled Chartplotter combines the function and benefits of both systems. However, there are hundreds of brands and models, so how do you know which one is best for you?

Fisherman with Prize Catch
Fisherman with Prize Catch

FishFinder Considerations

The type of system you should buy will depend on how and where you plan to use it. You should ask yourself the following questions before you make your purchase.

-How do you plan to use the combo unit? If you are using it primarily for boating, perhaps you don’t need a fishfinder. If you are using it mainly to plot your fishing trips, then a fishfinder is a definite must. Sport fishermen and commercial anglers will also have different needs. If you plan to use the device in a kayak, it will be smaller than if you are choosing one for a commercial fishing craft.

-Where do you boat and/or fish? The Chartplotter model that you choose will depend on whether you are fishing small inland lakes, large lakes, or oceans. Some models have transducers with greater depth capabilities; others can integrate the many systems on your boat into one display to make navigation on challenging water easier. -Will you need your hands free to paddle, steer, or work other devices? If not, then a handheld device might be the appropriate choice for you. If you will need your hands, then you should consider purchasing a device that you can mount on your craft. If you already have a number of gadgets mounted on the boat, then you should consider a multi-functional display unit.

Once you’ve made the big decision of whether you want a handheld, a mounted device, or a multi-functional Fish Finder display, then you need to consider the more detail-oriented preferences.

-What FishFinder display size is right for your boat? Display size is a primary consideration because the display is how you will interact with your device. If the display is too small for you to see easily, it will not be a useful tool. However, if the display is too large, it may not fit in a smaller vessel, or it might get in your way. Some captains advocate that bigger is better in a Chartplotter display, while others claim that small phone-sized displays are perfectly functional.

In addition, you need to consider the screen resolution for your device. Screens with higher resolution and bright displays will be easier for you to see, especially on sunny days. Your best bet is to choose a display that fits your boat and your vision needs. Choose a plotter with a screen that is big enough for you to easily read the information that it provides you and small enough that it fits easily on your boat without crowding your space or your other instruments.

-Do you prefer touch screens or buttons? We all have our preferences, and when you are attempting to use the screen on the water, it is important that you are comfortable. This choice is truly a matter of personal preference. There is no advantage of one over the other.

-Do you have other electronic devices that you would like to integrate with your Chart plotter? If you do, then you should consider a multi-function display unit which meets the NMEA 2000 standard. This type of unit will allow you to display not only your charts but also your fuel levels, water temperature, and tide charts. Weather information can also be useful when you are out on the water and can be integrated into your display. Having all of this information integrated into one display keeps from cluttering your helm.

-How much information do you want to process at a time? This question not only gets at how much information you want to see but also at how fast you want to see that information. If you want as much information as a multi-function display plotter can give you, then you will need one with increased memory and processing speed. The less information you want, the less you need to worry about the CPU (Central Processing Unit) capabilities of the device.

-Do you want to be able to connect other devices such as your smartphone to your Chartplotter? If you, you should probably consider getting one with WiFi capability. This tool can even offer apps that allow you to access the system’s data and/or control the system from your phone.

-How long will you be between ports? If you will be on long fishing or boating trips, it is important that you choose a system with long battery life or with a back-up battery.

-Do you want alerts from your plotter? Some devices will set off alarms or give alerts to the captain. For example, do you want an alarm to sound if the boat enters dangerously shallow water? If so, then purchasing a unit with alarm capabilities is a good idea.

-How likely is it that your unit will get wet? Chances are that the answer to this question is “very likely.” After all Chartplotter devices are used and mounted on boats which spend their time surrounded by water. For this reason, it is important to consider whether or not the device you are buying is waterproof and floatable. Both of these features will save you money in the future. -How much money do you have to spend? These units can vary from a few hundred to a few thousand dollars. Be sure to keep your budget in mind as you choose your unit.

The following companies make these units with Global Positioning System capabilities: Garmin, Lowrance, Simrad, Furuno, Raymarine, and Hummingbird, among others. For specific 2019 product reviews, you can visit our site for unbised reviews.

A FishFinder,GPS, Chartplotter Combo is a Valuable Fishing Tool

I saved the most important consideration, whether or not your Fish Finder should have a Chartplotter and GPS, for last. If you are a sport or commercial fisherman, the answer is an unequivocal “YES!” Fish Finder GPS Chartplotters combos are a great choice, especially for boats or crafts with limited space at the helm. These combo units save space, and they provide all the benefits of a Fish Finder, the navigation enabled plotter and the benefits of GPS.

Because Fish Finders use sonar to allow you to see what’s in the water under and around your boat, they detect the size and kind of fish in the water below your boat, allowing you to isolate places where you are more likely to make a catch. A Finder can scan and give you detailed information about the number of fish in an area as well.

Also, a Fish Finder can help you to locate the structures and cover that attract fish and allow them to hide. Many fishermen get into trouble as they search areas with cover and structure because they don’t know the depth of the water. A Fishfinder, Charplotter, GPS Combo gives depth readings, which not only help you to locate the fish but also help you to avoid hitting shoals or tangling your motor in the weeds.

Combining the sonar technology of the Fish Finder with navigational technology of a Chartplotter and GPS allows you as a fisherman to find and track the fish. The unit will allow you to save the routes on which you have had success so that you can go back and fish them again.

If your device is also a multi-functional display unit, you can track the temperature of the water at the time you caught the fish, the distance between places where you caught the fish, the time when they were biting, and the speed at which you traveled between waypoints. All of this information will make it more likely that you will have a safe, productive, and repeatable fishing trip.


These combo units are great because they combine the best features from marine technology into one very poweful tool. The FishFinder Chartplotter, GPS Combo is definitely the most economical and practical tool for fishermen today. You can have the benefit of all three tools at one affordable price.

We all have memories of our child hood experiences. Some people remember their parents reading them bedtime stories, using different voices for different characters. For me it’s fishing with my dad.

It’s the memory of my dad showing me a nautical chart. Seeing the muted blues, tans, greens, and yellows of a nautical chart takes me back to nights at the cabin sitting next to my dad. He used to spread the charts out in a half-circle around him, looking for inland lakes and new routes to his favorite fishing holes. The paper charts were so well used that the paper frayed at the fold creases. They smelled, like my dad did, of smoke, fish scales, and wool.

He would take his metal ruler and measure out the nautical miles. He took notes in a small, spiral-bound journal that he kept in his tackle box, jotting down information about depth, shoals, island numbers, and buoys. All the while, he talked to me about contour lines, symbols, numbers, and how to use the scale.

I still have those charts; although now several of them are framed and hang on the walls of our cabin. I don’t take them out at night to plan my routes. While I learned a lot about how to chart waters and how to plan a fishing or boating trip, my new dash-mounted GPS, Fish Finder, Chartplotter system gives me so much information at the click of a button that it would take me hours to acquire using paper charts.

Just remember there are so many factors to consider when choosing a navigation enabled Fish Finder Combo that it may take you a while to do your research. However, it’s time well spent. Maybe this is my dad talking, but it’s better to be safe than sorry. Whether your alternate method of navigation is to use paper charts, a compass, coastal navigation, or celestial navigation, be sure you are prepared with the necessary supplies packed on your boat in case you lose power. After all, people navigated the waters for hundreds of years without electronic gadgets, so you definitely should not panic if you lose power.

In case you have never traveled without a navigation system, I’ve included a couple of tutorials that will help you feel more comfortable in the event you need to find your way technology-free. BoatUS offers some sage and easily understandable advice about how to read paper charts. provides some simple instructions for using a marine compass.

If you get caught on the water at night coming home from a fishing trip, celestial navigation skills can be helpful. The website Soundings can help you learn the basics. Finally, if you would like to learn coastal navigation, offers courses designed for both American and Canadian boaters.

While technology makes traveling on the water a relatively simple process, it’s still important to you safety to learn alternate methods of nautical navigation. Plus, there is nothing quite as beautiful or as comforting as the sights, sounds, and smells of a well-worn nautical chart.

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