top of page
  • Writer's pictureDave LeGear

GARMIN vs. SIMRAD - What you need to know.

SIMRAD with FMT chip running

Wherever you plan on boating, an excellent marine GPS is crucial to getting around unfamiliar waters without running aground! But no sooner than you decide to get a GPS, you’re forced to make another: Which GPS should you get?

In this article, we will make some gear comparisons. It was written with the help of our friends over at FMT / Isla Mapping.

There are dozens of brand names and model numbers on the market, each with pros and cons. In this article, we’ll compare Garmin Units vs. comparable units manufactured by Navico, Inc., such as Simrad and Lowrance, to see which is best for your boating needs. We focused on units with display sizes between 9 and 12 inches with prices from about $1,000 to $4,000, but the points made herein also apply to the highest-end equipment they produce.

Company Histories

First, let's look at the history and background of each brand.

Garmin was founded in 1989, headquartered in Switzerland, and has a US headquarters in Olathe, Kansas. The company started as a producer of GPS units for the aviation industry, but it quickly expanded into other markets such as marine, automotive, and outdoor recreation. Marine Chartplotters they have several different product lines with varying functional differences and overall specifications. Today, Garmin is a global company with over 13,000 employees and a diverse portfolio of products that includes GPS-enabled watches, fitness trackers, in-car navigation systems, and much more.

Navico is a Norwegian company still based in Norway with a long history in the marine electronics industry. Navico was founded in 1947 and has produced navigation and communication equipment ever since. It was acquired recently by Brunswick Corporation, which makes Mercury outboards, fitness equipment, and 17 boat and watercraft brands, such as Sea Ray Boston Whaler and Lund. Like Garmin, Brunswick also has about 13,000 employees worldwide, of which about 1,800 work for Navico. Navico manufactures only Marine Electronics and produces Simrad, Lowrance, B&G Chartplotters, and all associated accessories for the equipment, including radar and sonar. The Simrad brand has been more associated with saltwater use, and the Lowrance brand is mainly used and recognized by freshwater boaters, although there is a clear overlap between the two brands. B&G units are specifically designed with software for sailing vessels. Both companies are approximately equal in size and are publicly traded with long histories and excellent track records, and each has its own set of fans and loyal customers.

Garmin vs. Simrad Marine GPS

Now, let's compare some noteworthy differences and similarities between Garmin and Simrad Chartplotters...

In the current marketplace, there are clear fans of each brand, and the market is flooded with all kinds of rhetoric regarding the manufacturers and the units and which has the best performance concerning everything from ease of use to radar to sonar. At each price point, is there a difference between just general opinions from users and actual measurable performance between any of them? As is the case with many products, when you dig into the exact specifications of the hardware, get past the rhetoric promulgated by paid promoters and puffed-up advertising, and pull back the curtains to expose the hard truth regarding differences between Garmin units and Navico units, there are several lower-c minor differences. They create varying opinions across the market paradigm. A critical, unbiased analysis of the specs and spontaneous user feedback indicates that most differences are minor, with no prominent heads or tales winner on any point of comparison.

However, given their relative biases, the manufacturers would likely take issue with that statement. For instance, which has the best sonar, radar, or ease of use? Is one more accurate than the other? Is one more reliable? We find approximately an equal number of people with different opinions on different points of comparison for each brand.

At each price point, the two brands offer GPS units that are approximately equally capable in any area of comparison. The lower-cost manufacturing budget units are all about the same in terms of their resolution, which starts at about 384,000 pixels. The higher-cost manufacturers have resolutions as high as 1,024,000 pixels, and the 16” displays and larger provide more than 2,000,000 pixels of resolution. That is a dramatic difference and one that should be noted. Higher resolution displays allow a boater to see more around their position at the same zoom level as lower resolution displays, providing superior situational awareness. They can render more fine details only if the loaded charts provide sufficient resolution. It should be noted that a high-resolution display cannot make a low-resolution chart product appear better than the same chart running in most lower-resolution displays. Thus, because CMAP and Navionics are generally lower resolution general reference chart options, those charts do not appear substantially superior on the higher quality vs. the lower quality displays. But it is nicer to view them on a larger screen.

It does not seem possible to convince a boater who spent $4,000 on his Garmin unit that the comparably priced Simrad unit has a better Sonar or a better radar, screen, etc. Conversely, the same is true for a boater who spent the same on his Simrad. Many are adamant in their opinions, and it seems virtually impossible to alter them or prove anything because the differences between user experience with their eyes and actual use of the water between these points of comparison are minuscule in the first place. Most are not comparing the units side by side as well. They only know what they know, and if their experience is relegated to only one, and that is the limit of it, that is what they say they prefer. They champion the product they have, and that is just human nature. Comparing Garmin Navico is like comparing Chevy to Ford, Coke to Pepsi, or McDonald's to Burger King. Everyone has their favorite and their opinions.

Concerning Radar (for the Offshore Community), we think Simrad has a slight edge on clarity and bird separation. Concerning Sonar, we think Simrad also has a slight edge, but it’s close regarding ease of use and intuitive functions, it's very close. Still, Garmin has a slight advantage for new users based on posted market feedback, but it becomes a wash once a user is equally familiar with the software in both and how the touchscreen menus are organized. If you are familiar with the software in each and the menu organization, we think the two brands tie in actual ease of use.

Switching from one to the other is similar to switching from an iPhone to a Samsung - once you use it for a few days, both are similarly easy to navigate as you quickly get used to what you are using. In many cases, YouTube has some great tutorial videos on the subject to help bring you up to speed.

The machines are all touch screen menu driven, and most have buttons and knobs. The machines function equally well and are equally reliable, although there are reports on both sides of bad experiences. When it comes to customer support, Garmin wins this contest. Navico loses as too much of their support is based overseas, and the communication is often tedious and challenging with many handling calls, and English is not their first language. For lack of any education about GPS, most GPS novices new to boating choose Garmin just due to name recognition, thinking that they indeed are the best or at least as good as any other machine.

However, there is one monumental glaring difference between Garmin and Navico units that many boaters unfortunately realize too late and there is zero question or debate about it because it is an undeniable truth that has existed for over a decade. For those boaters who understand this key difference, it makes the Garmin vs. Navico decision super easy, as they do know which manufacturer wins this long-standing contest. For those who don’t and just buy blindly, many end up angry and frustrated. So, stay tuned. We will reveal and discuss this important detail herein.

GPS Accuracy and Basic Charts Provided

There is no difference in the accuracy of any of the manufacturer’s units themselves. In 2000 the Department of Defense ended its practice of making GPS purposefully inaccurate and the systems suddenly became about 10 times more accurate leading to a revolution in many industries, including recreational boating. Both manufacturer’s units are now highly accurate as is the performance speed at each price point. All the units by Garmin and Navico will show the boat position at the same coordinates within a few feet. However, an important distinction to recognize is each unit may be running a different chart and therefore the rendered relative position of the boat on each chart may appear different. This is due to inaccuracies in the chart, not the GPS itself.

Both manufacturers provide units that have a slot(s) for mapping chips and provide a mapping system already installed for those who do not want to use a mapping chip. The slots can be used to, create data for backup or to run a variety of charts that may be purchased separately. Most Navico units provide a basic version of their proprietary CMAP charts as well as a very elementary version of a Navionics chart already installed as part of their offerings. Garmin provides a base version of their proprietary Navionics chart as well.

Navionics used to be a separate mapping company based in Italy, and a few years ago, Garmin purchased Navionics. Garmin now provides versions of those Navionics charts as their brand name chart. So Navico promotes CMAP, and Garmin promotes Navionics. What is interesting and especially critical is that most Navico units currently can run CMAP, Navionic, and other charts, too, but Garmin only supports them concerning charts. Very recently, however, Navico released a new unit called the NSX which only runs CMAP, and it may be that all the future models to come from Navico will also not support Navionics. The future at Navico is to move away from supporting Garmin’s chart. But all of Navico’s older models should continue to support both options and other charts as well.

Charting Differences

Garmin has developed a reputation for having poor chart accuracy in many inshore areas as any Google search can attest. This is an especially important shortcoming for Garmin, and it can be a very frustrating ordeal for any inshore boater who has a Garmin and wants to go to some out-of-the-way destinations. It is not a matter of opinion—like perhaps a view of a radar screen or sonar screen that is very similar between manufacturers. The charts speak for themselves, and they either are correct with requisite detail in the area of focus, or they are not. If you are running in 4 feet of clean water and the chart shows your position in the trees or up on a bank it is a problem, and no one can credibly argue otherwise. There are countless threads of numerous blogs going back for many years entitled something like “My Garmin shows me running on land”. The Garmin proprietary charts including their premium Navionics charts do have some substantive accuracy problems and it is painfully obvious when zooming in on many areas near shore when you are there in that place. For instance, if your boat is tied up to a seawall at a gas pump, the unit should display your position on the map at the seawall and not on top of the pumps or worse. If you are running in a tiny canal, it should show you in the canal and not in the mangroves, and if you are running a clear channel, the chart should not show you up on a flat. Garmin charts are famous for embarrassing inaccuracies just like those and Garmin has failed to address them going back for many years.

If you have been boating for a long time, you surely have at least heard of comments like that, if not experienced it yourself. It is primarily an inshore problem but there are some reported areas of glaring inaccuracies offshore as well. For instance, in the Bahamas, Garmin reported some depths in a certain area hundreds of feet off of actual and it remained that way for years despite many numerous posted online complaints. The complaints continue to be posted all over and Garmin always refuses to acknowledge any issue with their charts at all ignoring all the complaints with no publicized comments at all other than more positive ads. The modus operandi at Garmin cartography support who fields chart customer inquiries and complaints seems to be to acknowledge nothing and deny everything just using a stated difference of opinion on most complaints. When confronted with hard chart differences on why something is wrong or missing, there are plenty of obliques and general “we’ll look into it” types of answers. It is clear they never admit to any issues as something substantive.

The accuracy issue is generally discovered too late by boaters, and it should also be noted that that can only happen once they are finally on the water. These problems are not obvious online or in a store or viewing charts at home. If you look at the Navionics chart itself displayed on the screen in the store, it looks great and professional. And it is particularly so in deeper water areas where they provide lots of perfectly drawn depth contours, making the chart appear super detailed. The initial impression is good, so the setup for the disappointment of many inshore boaters new to boating is ripe for frustration. However, suppose the chart has aerial imagery provided. In that case, the quality of the images can be viewed for what it is anywhere, and that should be a clue because, despite the advertisements, the images provided are not high quality as they are typically hard to interpret in many places. They go fuzzy when zoomed, creating lots of uncertainty for any place unfamiliar.

CMAP is not much better in the accuracy or detail area or the imagery either inshore but they have a smaller user following overall so there are fewer comments to read about CMAP. CMAP provides shaded relief data offshore as well as some aerial imagery and lots of depth contours. just like Navionics. It is similar in appearance to Navionics, but most see the Navionics product as slightly more visually appealing. Not many Navico users are choosing CMAP as their clear map of choice for running in Louisiana or the inshore areas of the Gulf Coast and particularly Florida.

So, what is the bottom line of CMAP vs. Navionics? Offshore, we think it’s a tie or we give the slight edge to CMAP because CMAP did not have the offshore depth accuracy issue in some places, and the shaded relief data they provide is the same. Both get a grade of B or B+ offshore. But for challenging inshore areas around the SE USA and other areas worldwide, they both fail as both cannot be used for any clear navigation insight outside of main marked passages, and the images they both provide are mostly poor quality and go fuzzy. Both charts provide only a general idea of how to run challenging environments. Along with that lack of detail comes uncertainty and anxiety for any boater running unfamiliar waters. Thus, if you are an inshore boater, you should be aware of it. CMAP and Navionics are insufficient charts for challenging inshore waters and may be dangerous. They are better than using nothing but are general references only. They work great if you want to run the ICW or go from Miami to the West End of the Bahamas. But if you want to know exactly how to get from Islamorada to Snake Bight or from Naples to Hells Bay or from Homosassa to Crystal River on the inside or into the creeks around Matanzas Inlet or how best to negotiate the numerous oyster bars around Flagler Beach, they overall are very poor tools to use.

Perhaps that is why both manufacturers provide a disclaimer that the user should NOT rely on the chart for navigation.

We think that is an excuse. Why not make a chart that IS reliable like those in vehicles? For as big as these two companies are with thousands of employees and large market capitalization, is that too much to ask? It has been this way for many years. Hence, it appears it IS too much to ask, and that frustrates countless customers who thought their CMAP or Navionics would solve their navigation problems and found out it just was not the case. They were misinformed by the specious marketing, disingenuous ads, and/or perhaps an unknowing salesperson who sold them. None of those concerns are on the radar of blue water boaters who run large boats and do not see the chart problems inshore as they run only in and out of main marked channels to hundreds or thousands of feet and back again.

And what about that neighbor who says, “Hey,, my Garmin chart is fantastic or my CMAP is awesome. I have been using it to run all kinds of crazy places for years. I can get anywhere using it with no problem. I don’t know what you are talking about, and I think you might be wrong.” Again, once you dig in a little and ask some pointed questions, it is obvious those folks with that perspective are not using the chart provided to navigate and make decisions. Their argument is specious because they are using their own data points; they created that overlay on top of the provided chart. Their general reference chart is merely a placeholder for their waypoints and tracks, which they use to make decisions to get around. If they did not have the user-created data they assembled over time displayed to follow they would not be able to make the same runs consistently and particularly in poor visibility.

Most of their displays look like a mess as well, with spaghetti trails of user-created data all over the place.

So, they are not running the chart itself, but rather their data that displays on top of the chart to provide the information needed to run safely. Without this user data displayed, many would have real problems navigating. Do not try this with Navionics or CMAP, and no other created data waypoints or tracks to follow in any shallow area outside a main marked channel or where you see you are in deep water. It is not dangerous unless you are an expert at running the area. However, it is possible with a good, highly accurate, and sufficiently detailed chart, and we are getting to that shortly.

The Bottom Line

So, what is the bottom line between Garmin and Simrad, and which should you get since it seems to be close to a tossup based on the above? The units are very similar, and so are CMAP and Navionics. Well, another difference between the two brands is far more important than any of the differences noted above. That difference is the ability or lack thereof to run third-party-provided charts, i.e., charts not created and controlled by Garmin or Navico. If the user intends to use the GPS as a chart plotter (which is the case for nearly all boaters), the unit's utility can only be as good as the chart the unit is displaying.

If the chart is poor for the area being run, the utility of the GPS is poor no matter how expensive or capable the unit hardware may be.

The logical way to shop for a new GPS is first to pick the chart or charts you want to run,, and only after that is done, pick a unit that will run it. Garmin mandates that all their customers use Navionics and there are no exceptions. Garmin GPS units are not compatible with any 3rd party mapping systems.

Navico on the other hand does support a plethora of mapping options by other manufacturers including Navionics (except the NSX model and this will likely be addressed within a year). It is due to this glaring hole in the Garmin business paradigm that Navico wins this overall contest hands down for all inshore boaters. The “one chart only” policy costs Garmin big with thousands of customers fleeing Garmin annually to the Navico line of Chartplotters due to the Garmin mapping and lack of 3rd party options. These former Garmin owners do not dislike their Garmin GPS. Rather they dislike the chart that covers the provide area that they are mandated to use. So, they leave the platform to get a different map that works much better.

Educated GPS customers want mapping options because there is no one perfect chart and there are different kinds of charts that may be used in most Navico Chartplotters like Simrad as well which specialize in different regions and different areas of focus. For instance, some charts primarily rolled shaded relief data offshore that are higher resolution and more detailed than what CMAP and Navionics provides and that also includes proprietary data.

Another company that focuses on inshore is ISLA Mapping LLC, which produces Florida Marine Tracks and Louisiana Marine Tracks charts.

These charts quickly overtook Florida and Louisiana as the gold standard for inshore boaters. Now run by nearly 10,000 boaters in the SE, ISLA Mapping provides the highest quality aerial data inshore, focusing on properly navigating the most challenging areas and providing local navigation features and information such as signs, posts, and PVC stakes. Its hallmark feature is tens of thousands of miles of precisely drawn tracks that run pretty much anywhere an inshore boater would want to go. The ISLA story goes back about a decade. What is so interesting about it is that the genesis of their mapping endeavors is tied directly to the failure of Garmin/Navionics on their charts. The ISLA charts were created by a banker who was so dissatisfied with his Garmin charts and the feckless responses he got from Garmin over trying to get his charting problems fixed, that he just went ahead and created his own. You can hear more in our audio article on the entire progression below.

Since the ISLA charts were released, they converted more than 1,000 Garmin customers annually to Simrad and Lowrance who also have similar feelings about their Garmin charts.

FMT chart screen shot

There are several boutique specialized charts out there around the world that are running on Simrad and provide outstanding details and insight. ISLA Mapping is just one of more than a dozen. Any manufacturer who provides charts that are not the overall best (and Navionics is clearly not in the opinion of many) and provides only a single option will always compete at a disadvantage to competition that provides access to chart options. The market behavior of many thousands of Garmin customers selling their equipment and fleeing to the Navico platform in 2022 alone just due to the shortcomings of Navionics is evidence enough to prove the point.

The truth is, for most boaters, the chart is more important to them than the GPS running it!

Unfortunately, many boaters don’t realize it until they are forced to run a chart that fails to provide what they are looking for. It is a tough pill for anyone to swallow when they realize that their new Garmin equipment does not support what they want, and they have to spend more to get it by adding another unit or replacing their Garmin. It must be the same for all manufacturers of Chartplotters as well, recognizing that even after all of the time and effort they spend making the best units they can make and fine-tuning them with new technology every year, the consumer’s purchase decision may still be driven exclusively by the chart the customer wants to run and not the machine itself.


Garmin and Navico make highly comparable units at similar price points, and aside from charts, it’s very close to a tie when all points of comparison are considered. However, when charts are considered, there is no advantage to getting a Garmin as their platform supports only Garmin charts for use. This is an enormous disadvantage, particularly for inshore boaters. By comparison, most Navico units, including most of the Simrad line, support third-party and many different mapping options, including the FMT- chart. Thus, Simrad owners have an edge due to the option to purchase additional maps from various quality manufacturers.

It is particularly a point of distinction in Florida, which is Navico’s deepest market, where there are several high-quality, very detailed charts with a very strong following that run on the Navico product line, much to the disappointment of many Garmin customers who cannot run them. Remarkably, Garmin does not appear to give much concern about this as they double down annually on the one chart playbook. That seems fine for Navico, who enjoys millions in additional revenue each year because of capturing so many former Garmin customers who purchase their Chartplotters!

SIMRAD with FMT chip running

In the meantime,

We invite you to take in a few other Flats Nation Podcast Episodes to help "Scratch that Fishing Itch" when working or traveling and you cannot hitch up the Skiff and go, on these links:

Our main podcast page works great for your mobile device since it will stream right on your phone/tablet. It can be found by clicking Here

Our new Flats Nation YouTube Channel can be found by clicking here and sharing it with family and friends if you find it entertaining and educational! We have some great guests in the works and planning stages on a wide range of topics and product coverage soon.

Also, The "Flats Nation" Merch and Swag collection, if you like our content, has some new works, from T-shirts to our newer Technical wear, just in time for Tarpon Season, which can be found Here.

Tight Lines, and God Bless!

Dave and the Team.

Flats Nation Flag


Recent Posts

See All


bottom of page