MAPTATTOO GPS Review

Article by Jerry Culik

I recently got a chance to mess around with a new handheld marine GPS. I’m going to call it a chartplotter because it’s a tablet-sized device and has a huge display compared to my Garmin 79 handheld. From the MAPTATTOO website: “With its E Ink Screen, readable in sunlight, usable with wet fingers, and with exceptional battery life, it is the navigation aid for your next adventure.” That’s a mighty bold set of claims, but they’re coming from Erwan Kerebel, who saw the need for something better: “We designed MAPTATTOO after having raced to Alaska from Port Townsend, WA on a 20-ft row and sail boat. We used Navionics on an iPhone back then and realized the flaws of using a smartphone on a small boat. Hard to read in direct sunlight, poor battery life and difficult to operate in a wet environment.” MAPTATTOO addresses all of those issues.

Right out of the box the device looked as good as it does on their website, and it was packaged like you’d expect an expensive internet device to be. Included with the chartplotter, which resided in a protective soft case, were two USB cords for communication and battery charging. Don’t lose them, because the plug for the MAPTATTOO end has a red silicone O-ring to produce a waterproof seal while it’s connected…and the usual USB-C plug just falls out. With the plug removed, there’s a captive cover to seal the device to an IP68 rating. The MAPTATTOO has an energy-efficient monochrome EPD (electrophoretic ink display) that continuously shows speed, heading and track. It also has a replaceable 5,000 mA-hr lithium-ion battery that can, according to the specs, keep the device powered up and chartplotting for around 50 hours. My “fully-featured” Garmin handheld, with its 3” color display, would have required several sets of batteries to do that. So there you go, the best thing about the MAPTATTOO is that you can leave it turned on, and you don’t need to carry around a bunch of spare AA batteries – or worry about changing them mid-sail.

Like a Kindle and other ebook readers, MAPTATTOO’s display uses power only when it’s updating. My MAPTATTOO actually ran for about 55 hours; with the white LED backlighting set on “high” my MAPTATTOO ran for more than 48 hours, just a little less than the spec of 50 hours. Over a couple of days of sailing, with continuous speed, heading, and charting, the power gauge dipped to just 70%. After fully discharging the battery, it took about five hours to charge it back up when plugged into the USB-C port of my portable power station, which is indicated by a steady blue LED. In addition to the 50 hours of continuous operation, the specs say it has a “power-save” mode. But after questioning him about that particular feature, Kerebel says it will be implemented in a future software release.

The MAPTATTOO chartplotter doesn’t use Navionics or any other smartphone charts. Instead, Kerebel uses proprietary software to convert NOAA and Aqua Map charts to a format that’s compatible with the EPD display. One set of charts of your choosing ships with the device. And you can add more for $39 a set; updates are free for a year (and, like a Chromebook, periodic updates to the MAPTATTOO software are free for the life of the device). As I am writing this there are 14 chart sets that cover the Atlantic and Pacific coasts of both the USA and Canada. There are also charts for the Great Lakes, the Canadian arctic, and inland lakes for both the USA and Canada. And there are even charts for the French Atlantic and Mediterranean coasts. At present the MAPTATTOO chart sets don’t cover the Mexican coasts or the Caribbean, although there are charts for Hawaii. Once the chart sets are loaded into its memory, the MAPTATTOO will automatically pull up the appropriate navigation data as you travel around the globe.

You might recall that our editor posted an interview with Kerebel last year (Navigation Device for Adventures on the Water) and asked him to tell us about the whys and wherefores of coming up with his MAPTATTOO chartplotter. Responding to a question about the durability of the screen and proprietary charts, Erwan wrote:

“A typical issue with UV exposure on screens is yellowing of the polycarbonate external layer. Under atmosphere, the cause is oxidation accelerated by UVAs and UVBs. Our screen is bonded to the glass, which protects the polycarbonate layer and prevent[s] oxidation (no oxygen). We are also adding a UV protection on our glass. We have been conducting accelerated UV exposure tests and are still conducting some. We will share the results.”

“Lastly, with regards to charts, we will release an online converter that our customers can use to convert standard S-57 [aka “ENC”] charts into our proprietary format. This will allow US customers to use charts available for free from NOAA.”

Since I didn’t find anything about this posted on MAPTATTOO website, I asked Kerebel about it and got a quick reply. Regarding the software for DIY chart conversions, nothing is going to be available in the short term…maybe in 2025. And he indicated that they saw no evidence of yellowing as a result of the accelerated UV exposure testing.

The MAPTATTOO is not a Kindle with charts. It’s a clean-sheet design that’s dedicated to chartplotting; and it’s produced and assembled in Chicago, IL using a small production batch process. The MAPTATTOO website explains more about the technical details and development process. The EPD has 1024x768, 212 ppi resolution (for reference, the current-model Kindle 11 has 1448x1072, 300 ppi resolution). It’s got an anti-reflective coating and I could see the 15 mm, high-contrast speed and heading numbers just fine while sitting and standing several feet away, even with the MAPTATTOO far from my direct line-of-sight. Although the GNSS engine is capable of using both Galileo (Euro) and GLONASS (Russian) constellations, the present firmware release only uses GPS data. There is no feature to choose or view reception info; a “scatter plot” generated by the trace was less than 150 meters when it sat inside my house for a day; outside, the trace dithered by only about 10 meters. The MAPTATTOO runs on a power-efficient ARM Cortex-A9 processor with 512 MB of RAM, and it has 32 GB of storage for charts and track logs. You can upload .gpx (“GPS Exchange” format) routes and waypoints and download your daily track data, also in .gpx format using the built-in USB-C port.

A short YouTube video (www.youtube.com/watch?v=hoDgOdxTr5o) gives you an idea of how they’re put together; another shows Kerebel repeatedly dropping a prototype onto a hard surface—without any damage (www.maptattoo.com/2023/11/02/impact-resistance). The E-ink display screen is bonded to a 1.1-mm thick Corning Gorilla Glass cover that’s “almost twice as strong as a typical smartphone or tablet.” A question I got from a user was, What happens if we sit (or step) on it? Like finding out if it’s really submersible to 1.5 meters for 30 minutes to test the IP68 rating, I’m not willing to find out; at least, not on purpose. But Erwan told me that they have not had to replace any displays after sending more than 300 of them out into the field since the original crowd-funded versions became available about a year ago (fall 2023).

As a real-time chartplotter, MAPTATTOO does everything that you’d expect it to do. Waypoints, check; routes, check; distance to and from waypoints, check; tracking, check; auto track save, check. But unlike any other chartplotter that’s out there, it’s portable; and it doesn’t need a power “leash.” To find out information on a buoy, you tap the screen. To store a waypoint, you also tap the screen. The MAPTATTOO does not have a dedicated MOB function. But if you click on a waypoint and “GO TO”, MAPTATTOO gives you the bearing and distance, and calculates how far off course you are. To clear a route, choose “PAGE” and “+/-”, which will then toggle between the route info and a clear screen.

One nice feature is the tide and current predictions that are shown right on the display. You don’t have to search for them like on a Garmin GPS. An “arrow” symbol shows the direction and strength of the current. Tapping the arrow gives the local time and direction of the tide. A “rectangular box” symbol indicates a tide station; tapping it provides the time and height. If there are several features in the chart area, you get a menu (e.g., “TIDE”, “CURRENT”, or “LIGHT”) to choose from, which will then show the details.

When you order a MAPTATTOO, you’ll get a note from Erwan Kerebel directing you to read the MAPTATTOO User Guide because it’s not included in the box. And you’ll need it to change the settings and to use all the features built into the device. The MAPTATTOO website has even more content: a list of FAQs, newsletters, travel stories, destination recommendations, and exclusive offers. There is on-line support, and you even get your own personal space where you can log a service ticket for issues, questions, or enhancement requests, download firmware updates, and download the chart updates. The most important point is that they want—and welcome—feedback and suggestions…totally unlike big boat GPS and chartplotter suppliers.

If you want to read more about how well the MAPTATTOO chartplotter works before you buy one, Ben Fuller got an early-production MAPTATTOO and wrote a review in the June 2024 issue of Small Boats Nation (see “Maptattoo”). He used his device while rowing his dory the previous fall, iceboating, and then rowing in the spring, so he had a fair amount of sea trial use before writing his detailed review. He suggested a bunch of changes to the charting, which were implemented in short order. Charlie Doane, author and cruising editor of Sail magazine, provided another useful review (“MAPTATTOO Nav Tablet”) on his “Wave Train” blog. So even the big boat folks have positive things to say about MAPTATTOO. I agree with most of his comments, and all the settings can now be changed right on the device, and right off the bat my MAPTATTOO knew how much power it had in the tank. When I checked YouTube, I found one test review, “Is this the future of kayak Navigation? Maptattoo” by Brett Friedman (aka “Adventure Otaku”). And there are a whole bunch of videos from Kerebel on MAPTATTOO’s design and production that were worth watching to understand his business approach.

My Shallow Water Sailor colleague, Bob McMichael, tried out the MAPTATTOO chartplotter on his Core Sound 15 row-sail out to Wye Island and back during the Mid-Atlantic Small Craft Festival in October. He loved it because he could see, in real time, improvements in speed and trim as he played the puffs and eddies along the Miles River. I’ve been using it while testing my electric outboard conversion, and as a portable chartplotter on my MacGregor 19 powersailer. In both cases, the MAPTATTOO is superior in just about every way to either a late-model Garmin handheld GPS or one of the older fishfinder/plotters. I can keep my eyes on the water while navigating, instead of pushing buttons. And, of course, I’ve got continuous, large readouts of speed and bearing, as well as speed to, heading to, heading correction, and ETA if I tap on a waypoint.

With so many great features, what did we find that we didn’t like? The blinking green LED does make it easier to find in the dark when the backlighting is off. But hitting the right button at night, even with backlighting, was challenging. I kept pressing the wrong button when I was trying to scroll the map. So using the screen swipe for that function is essential, although it might not work if you’re getting a lot of spray. Illuminating the buttons would help find them when you toggle the “Touch” setting to “No.” And Bob suggested that using a red backlighting LED would be better than white so that your night vision is not impacted. Since I don’t sail at night (at least, not intentionally), that’s not a show stopper. And I typically use the backlight to brighten up the screen whenever I’m out in cloudy weather (the backlighting LED, even when set to “HIGH,” uses a miniscule amount of power). The monochrome screen refreshes about once a second, which is a little disconcerting when you’re used to the color charting on a Garmin. It was not a big concern once I was out on the water. But the display’s refresh rate (when compared to a smartphone or a Garmin GPS) is a recurring criticism of MAPTATTOO, even though it’s an important component of its power-saving design. And it's something that will be addressed in future software releases…from Kerebel: “This is an area that we are currently heavily investing in. Our next firmware…will improve performance dramatically. We are seeing 50% improvements in many areas and are still working to improve.” Again, it was not a show stopper once I got used to it, and I’m looking forward to seeing what other new features will be added.

Both Bob and I were worried about losing the MAPTATTOO chartplotter, and Bob thought that more pronounced skid-proof feet would help keep it in place. The first thing I did was put a lanyard with a key float through the lash point. MAPTATTOO does offer a Quad Lock mount for an extra $59 when you order your MAPTATTOO (see quad-lock-mount-kit). And since it’s a standard-sized tablet (4.6” x 7.5”), there are bound to be plenty of aftermarket holders available that would fit. I think that tablet mounts from Mob Armor and RAM® Mounts would also work fine. A lower-cost alternative is Scosche’s magnetic MagicMount, or 3M’s Dual Lock™ Reclosable Fasteners. Robert Bieber got the 3D models from MAPTATTOO and used them to design a holder for a standard ¼” mount. He produced the holder on his 3D printer; and he has shared both the STL, STEP and FreeCAD files, if you want to modify it or make your own version (see www.printables.com/model/956378). I was concerned about the plug used to seal the USB port; with my luck, it’s just a matter of time before it will get ripped off. Erwan said that they’ve improved the material used for the plugs, and that they would gladly send a spare or two if anyone has an issue. It might be a good idea to carry one in my spares kit, but you’ll also need a small Torx screwdriver to replace it. And since they’re so small, maybe a couple of spare screws should be included with the cap.

Prior to getting the MAPTATTOO, and since Garmin software only loads onto laptops with Windows or Mac software, I never bothered with loading a course into or showing tracks from any of my Garmin GPS devices. But with the MAPTATTOO chartplotter’s built-in USB port and connection to my Chromebook, I’m now able to fairly easily generate and load a pre-planned course and view my tracks. MAPTATTOO records your track and creates one track file per calendar day (and the filename uses the date), and it automatically starts a new file at around midnight. Once you’re out sailing, the MAPTATTOO shows your track right on the screen. Turning the MAPTATTOO off and then back on will clear the track, and start a new one. So if you expect to return to your starting point (and haven’t stored it as a waypoint), it’s better to just leave the MAPTATTOO on.

I was initially concerned that turning it off and back on would cause an earlier track to be overwritten (and we did lose a track at one point), but I didn’t lose any track data after multiple restarts. The recorded tracks are stored as .gpx files in the MAPTATTOO’s DATA folder under the “Trace” subfolder with the date in the filename. My Chromebook easily converted the data files to tracks on Google Maps and NOAA charts using GPS Visualizer (recommended in the MAPTATTOO User Guide), which can also generate courses with waypoints. These routing files can be downloaded and accessed on the MAPTATTOO chartplotter by selecting the “ROUTE” button, which will show the last one that was used. If you subscribe to OpenCPN, you can use that, but I’m also experimenting with free on-line tools like gpx.studio. There are YouTube videos on how to use it and GPS Visualizer, and I think that one specifically on charting and routing using the MAPTATTOO would be very helpful for chartplotting rookies.

I managed to “kill” my MAPTATTOO by discharging it all the way to 0%. And after I recharged it, it wouldn’t start up. PANIC! Following the info in the user guide, I held the power button down until it shut off, waited about 15 seconds, then tried again. This time it started up right away! I grinned just like the image of British explorer Lt. Col. Henry Worsley MBE, sans cigar, who was happy to use GPS on his solo trek to the South Pole in 2016 (for an excellent article on Worsley and his adventures, see “The White Darkness” by David Grann in the New Yorker magazine). But while cruising out on the Chesapeake Bay, it unexpectedly locked up and stopped updating the speed/heading and track. I got it to function again after a couple of frustrating “cold start” attempts. Fortunately I was not in any danger, and I did not lose any track data. It balked at start-up one other time; but after a couple of “cold starts” it was able to finally get a satellite fix and carry on. Maybe it’s related to problems with satellite reception, or an issue in the software. Either way, the MAPTATTOO hiccupped, and then recovered. Another time it apparently didn’t shut down properly (a “locked up/frozen display”). After sitting for several days in that state it refused multiple attempts to start up, even while connected to my laptop with the blue “charging” LED lit. Thinking of the first time I had trouble starting the MAPTATTOO up, I tried charging it for two hours. When I was finally able to “cold start” the chartplotter, it was clear that the frozen display had completely discharged the battery. Since this episode didn’t happen out on the water, it was frustrating but not dangerous. Still, the unexpected battery drain from the locked-up display was unnerving, and it can easily trip you up if you’re not careful to make sure that it has shut down correctly (only when you see the “MAPTATTOO” logo on the screen). And if there is any problem starting up, assume that the battery is dead, and try charging it up for an hour or two before trying again. Kerebel’s recommendation, if the MAPTATTOO locks up or stops functioning, is: “Power OFF (long press on the ON/OFF key until the green LED turns OFF or for at least 6 seconds), wait 10 seconds and Power back ON, your device should restart properly.”

Previously I’ve used Garmin handheld GPSs on my dinghies, and I have a now-discontinued Echomap 44dv fishfinder/GPS on my bigger boat that requires 12VDC power. While I’ve frequently considered buying a smallish touchscreen chartplotter to replace the fishfinder, they’re bulky, use a lot of power, and are not particularly high-performance devices. The current-generation 6” Garmin Echomap, for example, draws about 1 amp of 12VDC power and has only 800x480 resolution (compared to 1024x768 on the MAPTATTOO chartplotter). The Garmin has no support, costs the same as a MAPTATTOO, and would be a permanent, power-leashed installation. And since I expect that the low-resolution Garmin chartplotter will be discontinued before too long (or replaced by a newer—read, more expensive—model), I’ve been reluctant to pull the “replace and upgrade” trigger. One nice feature of the chartplotters, even the small combos, is that you can use the transducer to set depth alarms—and an anchor alarm if your anchor starts dragging. And when I’m moving fast, or in dicey waters, having “another set of eyes” on rapidly decreasing depth sure is nice to have. Even though the MAPTATTOO has no depth transducer, the charted depth and tidal information is there. And an anchor alarm only needs GPS location data to function. Maybe one or both are something to look for in future updates.

Yes, the MAPTATTOO handheld chartplotter is expensive (although until this year’s Annapolis Sailboat Show, you could get a $100 discount off the $799 list price). And, yes, there’s always a risk that the MAPTATTOO’s maker—and the promised software updates—will disappear, like all too many startups with good ideas and great products. But Erwan Kerebel is clearly passionate about his baby, and he’s in it for the long haul. I think that MAPTATTOO is better than my Garmin handheld in every way, and the MAPTATTOO will surely get added features and improvements as more software updates are released. And if you need one more reason to justify the cost, it’s repairable. So if you do manage to crack the screen, blow the USB port seal, or kill the battery, you can get it repaired…for free during the first year warranty. And you don’t even need to pay for the shipping! Asked about the cost of repairs, Kerebel estimated that a battery replacement would run about $50, and a new display, assuming you can crack the Gorilla Glass, would be about $100 (to date, they have not had to make any of those repairs, so the actual costs haven’t been finalized). While the MAPTATTOO is pricey, it’s a major improvement over a handheld or fishfinder in every way. And it sure is nice to know that I can get it fixed, if the worst does happen. So maybe we should consider the MAPTATTOO chartplotter as a long-term investment, just like a boat. •SCA•