Have you ever brought up the chartplotter and depth sounder screens side by side, and cursed your digital charts for being so wrong? Can you even count the number of times you watched the boat icon cross over a contour or wreck, while depth readings proved that the bottom hadn't changed one bit? Have you run aground, when according to those electro-charts there was still plenty of water under the keel? We feel your pain, because we've been there, too. As incredibly good as modern digital chartography is, there are still plenty of errors in the data pool. Updates aren't always complete nor 100-percent accurate. Sand bars shift. New wrecks and reefs are created. It’s about time someone fixed all that—and that someone is named you.

digital charts

With Insight Genesis, you can create your own customized chart of your favorite fishing or cruising area. Join Lenny as he heads out into the Chesapeake Bay for an in-depth test of the system.


Up until now, you could choose from digital chartography supplied by the likes of Navionics or C-Map, the proprietary data of some electronics manufacturers, or geographically specific (and limited) providers like Lakemaster or Fishing Hotspots. Each has their own strengths and weaknesses. And while modifying pre-existing chartography data is possible in some cases, you've never been able to “build” your own personal 100-percent accurate and up-to-date digital charts. Until now.

Visionary Perspective

Insight Genesis, the creation of Navico (parent company of Lowrance, Simrad, and B & G), is a service that signifies a new age in digital chartography. It allows you to record your sonar and GPS readings, intertwine the two, and crunch the data to create custom-built digital charts from your very own pings and positions. The process is designed to be fairly simple: just insert a data card into your unit, hit record, and crisscross over an area to perform your own survey. Then pull the card, put it into your computer, and upload the data to the Insight Genesis web site. Give the site a few minutes to process the data, then follow a link via email to view the bathymetric chart you've just developed. Finally, download the info back onto the card and transfer it over to that magical box mounted at your helm. It sounded pretty neat to us, but here at boats.com we didn't want to merely re-hash press releases and pass on Navico’s claims to you—we decided to dig deeper, and try out Insight Genesis first-hand.

To find out just how well this system worked, or if it really worked at all, I headed for an area of the Chesapeake Bay where I knew the digital charts missed a beat or two. Years of fishing in the area had taught me there were fish-attracting humps and bumps that weren't in the standard digital database. Let’s take a look at what’s on-screen when looking at the pre-existing chartography:

lowrance and noaa chartography

My plotter’s built-in chartography is seen to port, and NOAA digitized raster chartography is to starboard.

As you can see, the standard chartography built into the unit’s brain before this experiment and the NOAA chart aren't exactly identical. Looking at the chartplotter screen you can see a clearly defined hole just south of the green marker, while NOAA shows a reading of 32’ west of the marker and one of 31' to its south. But, the depths don’t look radically different. So, why have I come here? Because I know that neither one hits the bulls-eye.  My mission is to see if I can create a chart that shows those missing humps and bumps, giving me additional detail about the fish-attracting structure here and thus improving my prowess as an angler.

The Day of Digitization

The area I want to cover is about a quarter of a mile long, and a third of a mile wide. After spending an hour or so studying the Insight Genesis Q & A and User’s Guide and watching a few how-to videos on YouTube, I learn that I’ll want to make passes no more than 65’ or so apart to ensure that the data collected by the sonar (both down-looking and side-scanning Structure Scan) thoroughly covers the bottom. I’ll need to make a series of parallel north-south sweeps until the entire area is covered, and to ensure the best results, then make a series of east-west sweeps covering the same chunk of water. I’ll need to keep my speed under 12 MPH for this to work, but since four to six MPH provides the best results, I’ll do the entire process at no-wake speeds.

As luck would have it, 65’ turns out to be just about how wide my passes are when I crank the wheel hard around at six MPH. I zoom in the chartplotter so I can track my progress, insert a chart card, and start collecting data. I can almost feel the beating of my sounder, as it pumps ultrasonic waves into the water at close to 5,000 feet per second. And as I slowly cruise along I notice humps and bumps that rise as shallow as 24’ in a spot that the pre-existing chartography insists is 30’. Hah!

The entire process takes me less than an hour, and creates a file that’s 542 MB. That’s a perfectly manageable size, and since Navico recommends logging files no longer than two hours at a time, using a common four gigabyte card gives me plenty of data stowage for charting twice as much surface area as I covered today. With my pings and positions securely recorded I drop a jig and catch a few stripers for dinner, before revving up the outboards and heading for the marina. My mind is rich with anticipation of seeing a chart—my chart—that shows every little rise and fall of the bottom. I’ll have an edge over all the other anglers around here and I’ll be out-fishing them in no time, because soon, with a glance at the screen I’ll be able to see what no one else sees. Or will I?

Data Debrief

After flushing out my outboards and giving the boat a quick rinse, I dart back to the office and insert the card into my computer. Figuring out how to upload the data file to the Insight Genesis system takes all of five minutes, but now I have to wait for the data-crunching cloud to do its thing. According to the User Guide, I should get an email within a half hour or so that includes a link to my new digital chart. And true to their word, the email comes through before I can finish filleting the stripers.

I click on the link, and boom—there’s an aerial satellite image of the bay with a pink and red square where I made my sweeps. I zoom in, and as the image becomes larger I can see my track crisscrossing through the square along with the depth readings I recorded.

But bathymetric data isn’t the only thing drawing my attention. A screen shot of my fishfinder appears on the right side of my computer screen, and a red dot on the satellite image shows the position of the boat where the fishfinder is currently displaying. By hitting the “play” button under the fishfinder, I can watch the history my sonar recorded; the red dot moves along my track line as the fishfinder screen scrolls, following the exact path I made while collecting the data. I can watch it in “real” time, or hit a fast-forward button and cruise the entire path in about 10 minutes. This feature turns out to be incredibly useful—about half way through I see a huge smudge fly across the fishfinder screen, re-wind it, and watch again at regular speed. I realize that I while on the water, I hadn’t noticed a school of fish sitting on this particular drop-off. With a click of the mouse, I create a waypoint at the spot. Even better, I discover that I can switch between transducer views at any time. This lets me view the fishfinder screen in either 200 kHz or 455/800 kHz, and compare the differences between traditional down-looking sonar and Structure Scan sonar.

The post-trip self-debriefing continued as I discovered additional abilities, one after another. With a click of the mouse I overlaid bottom density data, and suddenly I could see where shell beds changed over to mud bottom. Now I knew why fishing at one particular hump always seemed more productive than the others, and I discovered several promising new shell beds to try. With another click I changed the contour lines displayed from every three feet to every single foot. I added and removed waypoints, then added vegetation onto the display. Half an hour later, I figured I knew more about this little slice of the Chesapeake Bay than any captain alive.

digital charts

Just how much better was my self-obtained data? Here's the detail level I saw on the Insight Genesis web page.

As you can clearly see, my chart not only told a different story, it also had a thicker plot. While looking at the old chartography one would think there was a hole just south-west of the green marker that dropped down to 32’ at its deepest point, then rose up into the lower 20’s on the sides. On my newly-generated chart, however, you can clearly see the hole is more of a trough running north-south, and on the east side of it, there isn't a single ridge but a series of peaks that rise up into the mid to lower 20’s. It’s also far more evident where the sharper drop-offs and highest peaks are, which is a dead give-away as to where the best fishing spots are likely to be.

In any new system, naturally, there’s going to be room for improvement. And yes, I did find some with Insight Genesis. First off, the on-screen chart shows GPS coordinates for where your cursor is, not for the boat’s location. I found this a bit confusing at times, especially when I was trying to compare exact locations on the newly-generated digital chart to the same location on pre-existing chartography. I wish the GPS coordinates told me where the dot (my boat) was at any given time.

Secondly, clicking on the mouse to change the boat’s location gets a bit hairy, because the chart re-centers on your new location. The sudden shift made me lose track of where I was in relation to bottom features that slid off the screen as it re-centered.

Finally, I wished I had the ability to re-size the chart and fishfinder screens inside the web site window, and get rid of a static (and essentially useless) chart graphic that sits on the right side of the web page, wasting space. Fixed as these windows are, I constantly found myself having to scroll up, down, left, and right every time I made a minor adjustment or a change in the display.

Back to Bathymetrics

At this point of the experiment, having learned so much about this location in such a short period of time, I was already a true believer—if anyone wanted to take away my Insight Genesis, they’d have to pry it from my cold dead circuit board. But there was still one more phase in this mission: downloading my newly-created bathy chart from the Insight Genesis site, and uploading it back onto my chartplotter. This step of the system was a bit less intuitive than the others, but in less than an hour I figured out how to properly download and un-zip the file on the card, and transfer it back to my chartplotter.

chart with insight genesis

Here’s what I saw on-screen (at far right), side-by-side with those screen-shots we were looking at earlier of pre-loaded and NOAA chartography.

After gazing upon the magnificence of my home-baked bathymetrics, in addition to the superior detail level you probably also noticed that the green channel marker buoy icon has been replaced with a green “X”. What gives? The system didn't do that, I did. Actually, I nailed down its position via GPS coordinates, then Photoshopped the X on there to give you a point of reference. Because unfortunately, the marker didn't appear on the chartplotter screen. One draw-back to uploading your own Insight Genesis charts onto your chartplotter is the loss of data that you can’t collect with your fishfinder and GPS—things like markers, bridges, and pilings. There’s no way to input this additional data into the chartography you develop, and in fact, some data—including contour lines and depth readings in the immediate areas around your self-made chart—gets lost in the shuffle. In the specific area where I made this chart, outside of my search grid I found that I needed to move at least a quarter mile away, across a blank chartplotter screen, before the pre-recorded data I usually depend on started popping back up again.

According to Navico, this is a side-effect of plugging in your own chart card. “In Lowrance Chartplotters and MFDs the charts on a chip always take precedent over embedded charts,” explained Shane Colony, Product Manager of Content and Cartography for Navico. “It’s the same for chips which are intended as a supplement to the embedded charts.”

In other words, the area surrounding a survey remain blank on a home-made chip, and that blank area blocks out the built-in chartography data in your machine. But it won’t necessarily always be that way. Colony quickly followed up by saying “We’re constantly working to improve the interaction of embedded and supplemental charts.”

For the time being, the fix for this problem is a simple one: use standard-issue chartography when you’re navigating, and pop in your own digi-chart once you’ve arrived at the hotspot. Or, if you have a chart card from another supplier, like Navionics, you can split the chartplotter screen to show one view with your chart, and a second with theirs.

Does this issue present a slight inconvenience? Sure it does. But the advantages Insight Genesis provides more than make up for it. Swapping cards or views now and again is a lot better than looking for drop-offs or wrecks that exist on the chartplotter but don’t match up with the reality on your fishfinder screen. It’s a lot better than running aground, when your digital chartography tells you there’s still plenty of water beneath the keel. And it’s a lot better than relying on imperfect data when your life depends on it—or at the very least, your catch does.

Editor's Note: Some functions of Insight Genesis are free; others require a subscription fee ranging from $19.95 to $299.95/year at the time of publication. For more information, visit Insight Genesis.