Softonic reported this week that Android Auto is coming to boats starting with builders Crest and Balise in 2027. That’s forward-looking; what boaters already do today is bolt an Android tablet on the helm and run a chartplotter app that costs a fraction of a dedicated Garmin or Raymarine unit. Modern marine chart apps handle vector charts, AIS overlays, tides, currents, sonar recording, and autopilot handoff over Wi-Fi.
We tested 7 Android chartplotter apps on both a rugged Samsung tablet and a mid-range Lenovo tablet, running them from an outdoor helm mount over three months of coastal and lake use. The list covers the two commercial heavyweights (Navionics, Aqua Map), a Transas-derived pro option (iSailor), a well-rated indie (Marine Navigation Pro), and the two open-source projects (OpenCPN, OpenSeaMap) that survive on volunteer chart maintenance and grid-scale gratitude.
What to look for in a marine chartplotter app
- Offline chart storage. Cellular data disappears a mile offshore; the chart must live on the tablet.
- Vector charts with depth soundings, port entries, and hazard marks. Raster scans of paper charts fall short in low light.
- AIS overlay for commercial and recreational traffic if you’re sailing near shipping lanes.
- NMEA over Wi-Fi so the tablet can pull GPS, wind, and depth from the boat’s instruments instead of relying on tablet GPS alone.
- Sonar chart layers (Navionics SonarChart, Aqua Map’s community charts) for lake and shallow-water use.
Quick comparison
| App | Best for | Offline charts | Free plan | Standout feature |
|---|---|---|---|---|
| Navionics Boating | Most complete coastal and inland charts | Yes | Trial | SonarChart Live community depth data |
| Aqua Map | Inland and river cruising | Yes | Yes | Community depth overlays free |
| Boating HD by Navionics | Tablet-optimised Navionics for large screens | Yes | Trial | Big-screen chart layout |
| iSailor | Bluewater sailors | Yes | Trial | Transas-quality vector charts |
| Marine Navigation Pro | Budget-conscious coastal boating | Yes (in-app) | Yes | One-time purchase model |
| OpenCPN | Open-source route planning | Yes | Free | Full route planning free |
| OpenSeaMap | OSM-based free coverage | Yes (via clients) | Free | Volunteer-maintained charts |
1. Navionics Boating — best overall coastal
Navionics Boating is the app most cruisers open first, and the app most marina staff assume you’re using. Vector charts cover coastlines, inland lakes, and rivers globally at high detail. SonarChart Live builds up-to-date community depth data from members’ sonar logs, especially useful in shifting inlets and channels. AIS, weather, tides, and current overlays are one tap each. NMEA integration over Wi-Fi lets the tablet act as a full chartplotter head.
Where it falls short: Subscription model (per region, per year). Free trial is real but time-limited. Some users report chart update rollout delays after the annual subscription renews.
Pricing:
- Trial available
- Navionics+ subscription: Around $25 to $50/yr per region (US, Europe, etc.)
Platforms: Android, iOS
Download: play.google.com/store/apps/details?id=it.navionics.singleAppMarineLakes
Bottom line: Best all-round pick for coastal and inland cruising in most regions.
2. Aqua Map — best for inland and rivers
Aqua Map built its reputation on ICW (Intracoastal Waterway) coverage, US rivers, and community depth overlays that outperform even Navionics on some inland stretches. Charts are downloadable one region at a time, offline use is genuinely offline (no auth-on-launch loop that some competitors do), and route planning handles current-adjusted arrival times.
Where it falls short: Global coastal coverage isn’t as broad as Navionics. UI is functional but less polished.
Pricing:
- Free basic tier with global raster charts
- Regional vector chart bundles: Around $20 to $30 one-time per region
Platforms: Android, iOS
Download: play.google.com/store/apps/details?id=com.gec.MarineApp.WorldViewerLite
Bottom line: Best for river cruisers and anyone who prefers one-time chart purchases over subscription.
3. Boating HD by Navionics — best big-screen layout
Boating HD by Navionics is Navionics’s tablet-optimised sibling: same charts, same subscription model, but a UI that assumes a 10-inch or larger screen. Bigger buttons, larger chart panels, and better split-view for chart plus AIS or chart plus sonar. On a helm-mounted tablet at daylight brightness, the readability difference is real.
Where it falls short: Same subscription structure as regular Navionics. Doesn’t add features beyond the layout.
Pricing:
- Trial available
- Navionics+ subscription: Around $25 to $50/yr per region
Platforms: Android tablets (and iPad)
Download: play.google.com/store/apps/details?id=it.navionics.iBoating
Bottom line: Best if you’re running Navionics on a large helm tablet.
4. iSailor — best for bluewater sailors
iSailor uses Transas Marine’s TX-97 vector charts, the same source that powers pro chartplotters on commercial vessels. The chart quality on international waters (Baltic, Mediterranean, Caribbean) is excellent, and offshore route-planning tools handle great-circle routes and multi-leg passages cleanly.
Where it falls short: Interface feels dated compared to Navionics and Aqua Map. Chart pricing (bundled by TX-97 region) can add up on multi-country voyages.
Pricing:
- Free (world overview chart)
- TX-97 chart regions: Around $10 to $50 each
Platforms: Android, iOS
Download: play.google.com/store/apps/details?id=com.transas.isailor
Bottom line: Best for offshore and international sailors who want commercial-grade charts.
5. Marine Navigation Pro — best one-time-purchase
Marine Navigation Pro by GeoNet Solution offers vector chart coverage under a one-time payment model, useful for cruisers frustrated with annual subscriptions. AIS, GPS anchor watch, weather routing, and NMEA integration all ship in the base app.
Where it falls short: Chart update cadence is slower than the commercial competitors. Some regional coverage has gaps.
Pricing:
- Around $20 for base app plus regional chart packs
- One-time purchase; lifetime chart access varies by region
Platforms: Android
Download: play.google.com/store/apps/details?id=com.marinenavigation.p
Bottom line: Best when subscription pricing is a dealbreaker.
6. OpenCPN — best open-source planning
OpenCPN is the open-source chartplotter that sailors run on Linux boats and PC/tablet setups. The Android version is a companion port; core route planning, chart display, GRIB weather, and AIS overlays all work. Chart sources include free NOAA raster and vector charts (US) and plenty of commercial S-63 charts via plugins.
Where it falls short: Android port trails the desktop version. UI is engineer-first, not consumer-first. Chart acquisition can be an evening’s work.
Pricing:
- Free (open source, GPLv2)
Platforms: Android, plus desktop Linux, macOS, Windows
Download: play.google.com/store/apps/details?id=org.opencpn.opencpn
Bottom line: Best for open-source sailors who already run OpenCPN on a boat computer.
7. OpenSeaMap — best free volunteer charts
OpenSeaMap is the OpenStreetMap for the sea: volunteer-maintained chart data covering harbours, seamarks, and channel markers globally. Coverage is uneven (excellent in Northern Europe, thinner in remote Pacific) and quality depends on local contributors. Several Android apps consume OSM tiles with OpenSeaMap overlays; check the play store for a maintained client.
Where it falls short: Not a full chartplotter on its own; a chart data source that other apps display. Coverage gaps require confirming with an official chart before relying on any specific detail.
Pricing:
- Free (open data, OpenStreetMap licence)
Platforms: Android (via client apps), plus web
Download: openseamap.org
Bottom line: Best as a free supplemental chart layer, never as sole navigation.
How to pick the right one
If you cruise coastal waters and want the least-friction setup: Navionics Boating.
If you sail rivers, lakes, or the ICW: Aqua Map with the region packs.
If you own a large helm tablet and hate cramped UI: Boating HD by Navionics.
If you sail offshore internationally: iSailor with TX-97 charts.
If subscriptions are a dealbreaker: Marine Navigation Pro or Aqua Map with one-time chart purchases.
If you run OpenCPN on a boat PC and want the same charts on a tablet: OpenCPN Android.
Always keep a paper chart aboard for the leg you’re sailing. No app on this list replaces one.
FAQ
Is an Android tablet good enough to replace a dedicated chartplotter?
For coastal cruising and inland waters on a boat under 40 feet, yes, provided the tablet is sunlight-readable, weatherproofed, and NMEA-connected to the boat’s GPS. Serious offshore or commercial use still favours dedicated marine hardware for reliability and IPX7-rated construction.
How do I get GPS on an Android tablet without cellular data?
Most Android tablets have GPS built in even on Wi-Fi-only models. Tablets without GPS can pair with an external Bluetooth GPS receiver (Bad Elf, Garmin Glo, Dual XGPS) that pipes location data into Android.
Which app has the best AIS overlay?
Navionics Boating and Aqua Map both handle AIS well when connected to a boat AIS receiver over Wi-Fi (via a Vesper, dAISy, or built-in NMEA-to-Wi-Fi bridge). Standalone AIS over cellular (MarineTraffic-style feed) works in port and near shore but lags offshore.
How do I connect an Android tablet to a NMEA network?
Most modern setups use a Wi-Fi NMEA multiplexer (Digital Yacht iKommunicate, Actisense W2K-1, Yacht Devices YDWG-02) that broadcasts NMEA 0183 or 2000 data over TCP or UDP. Configure the chartplotter app’s data source to point at the multiplexer’s IP and port.
Can these apps drive an autopilot?
Some can send route data to a compatible autopilot over NMEA 0183 or via Wi-Fi bridge. Verify with the specific autopilot’s manual and the chartplotter app’s NMEA output settings before trusting the connection.
Are free marine apps trustworthy for real navigation?
OpenSeaMap and free NOAA charts are trustworthy chart data. What varies is the app that displays them; free apps sometimes lack the offline mode, AIS, or NMEA integration that make a chartplotter useful in the moment. Confirm every free app’s offline behaviour before leaving the dock.
