NMEA 2000 Boat Telemetry & Sail Performance
On Your Garmin Watch

SailorData supports a wide range of modern Garmin marine and multisport watches including: fēnix series (including 6S Pro, 6S Sapphire, 6S Pro Dual Power, 7 series, 8 series), epix (Gen 2) series, quatix series (including quatix 6X, quatix 6X Solar, quatix 6X Dual Power, quatix 7, 7 Pro, 7 Sapphire, 7X Solar, 8, 8 Pro), D2 Air X10, D2 Mach 1, D2 Mach 2 Pro, Approach S72 (43mm & 47mm), Approach S70 (42mm & 47mm), Approach S50, MARQ Aviator (Gen 2), MARQ Athlete (Gen 2) Carbon Edition, Forerunner 265, 265s, 570 (42 & 47mm), 945, 965, 970, tactix 7 series and tactix 8 AMOLED.

Phase 1 — Install the Data Field: Open the Garmin Connect IQ Store app on your smartphone. Search for "SailorData". Tap Download (you may need to accept permissions). Open the main Garmin Connect app and sync your watch to transfer the data field.

Phase 2 — Enable on your watch: Press the Start/Stop button to open the Activities list. Select the activity you want to customise (e.g. Sailing) but don't start the timer. Press and hold the Up/Menu button and select Settings → Data Screens → Add New. Select the 1-field layout box, scroll to Connect IQ, and choose SailorData. Press Back repeatedly to save.

Method 1 — Via Connect IQ Store app: Open the Connect IQ app → My Device → My Data Fields → SailorData → Settings. Adjust display, wind target, and NMEA2000 BLE bridge settings. Tap Save, then sync your watch in the Garmin Connect app.

Method 2 — On-watch settings menu: Go to the activity profile, press Up/Menu → Settings → Connect IQ Settings → SailorData. Note: Wind target and BLE bridge settings cannot be changed here, but you can check the firmware version of the bridge.

The three/four configurable number fields can show: COG (Course Over Ground), SOG (Speed Over Ground), STW (Speed Through Water, incl. polar performance relative to target speed), TWS (True Wind Speed), AWS (Apparent Wind Speed), TWA (True Wind Angle), AWA (Apparent Wind Angle), TWD (True Wind Direction), BRG (Bearing to waypoint), DTW (Distance To Waypoint), TTW (Time To Waypoint), XTE (Cross Track Error), VMG (Velocity Made Good), VMC (Velocity Made Good to Course), HDG (Heading), Depth, and Rudder Angle.

In addition, the dynamic visual bezel displays TWA (dark blue arrow), AWA (light blue arrow), BRG (orange dot), Rudder Angle (gray bow) and toggleable visual XTE indicator plus green and red tactical wind shift zone markers.

Profiles allow you to save different data screen layouts (such as "3-field / 4-field", "XTE Indicator on/off", or "selection of data fields") and switch between them easily.

To configure them, open the Connect IQ settings on your phone or watch, configure the display parameters under "Profile 1" or "Profile 2".

Then select the active profile in the ConnectIQ settings on your watch for the selcted Activity. You can assign the SailorData data field to munltiple Activities. Each Activity can have one of the two profiles assigned, so that you always have the right layout for your Activity.

A visual badge on the display shows you which profile is selected. The badge disapears as soon as you start the timer of the Activity.

There are two ways to switch between display layouts:

1. You can use the Lap button on your watch to cycle through available display layouts during an activity. This requires that you enable the feature in the Connect IQ app settings.

2. Alternatively, in the Connect IQ settings on your watch, you can quickly switch between two different display layouts for the same activity by using the profile switching functionality.

You can enable Offline Demo mode through the Connect IQ app settings on your phone. In the SailorData settings, toggle "Enable Offline Demo Mode" to true and save. Your watch will run a local simulation of speed, depth, and wind data without requiring a connection to the hardware bridge.

Below is an overview of all configurable settings available in the Garmin Connect IQ app for SailorData:

The SailorData Garmin application supports a wide range of real-time marine telemetry fields. To display these values on your wrist, your vessel's NMEA2000 network must have the corresponding physical sensors installed to broadcast the data to the bridge.

¹ True Wind (TWA/TWS) calculation is a vector calculation that requires both a Speed Through Water (STW) paddlewheel sensor and a Wind Sensor. If STW is unavailable, it falls back to using GPS Speed Over Ground (SOG), though this will not account for tidal currents. The Heading (Compass) sensor is only required for the True Wind Direction (TWD) calculation in addition to the other sensors required for True Wind calculations.

² VMG and VMC calculations depend on active waypoint navigation and route details received from your GPS / Chartplotter.

Installation is a simple plug-and-play process:

1. Insert a T-connector into your existing NMEA 2000 (NMEA2000) network backbone.
2. Connect a drop cable to the open port on the T-connector.
3. Plug the other end of the drop cable into the SailorData Bridge.

The bridge is powered directly by the NMEA 2000 network. As soon as it is plugged in it powers on and begins broadcasting. Open an activity on your Garmin marine watch with the SailorData field enabled — it will connect automatically and your live vessel data will appear.

• Transmission range I have measured a transmission range of up to 8 meters on my boat with the bridge installed behind the power panel in the cabin in the center of the boat.
  That should be sufficient for sailboats up 45-50 feet. Of course depending on the boat's construction and materials, the range may vary.
• Power consumption The bridge consumes approximately 80mA at 12V.

Phase 1 — Download latest firmware: Download the latest firmware binary file for the SailorData Bridge to your phone or computer.

Phase 2 — Trigger update mode: With SailorData running on your watch, open the Connect IQ app on your phone and navigate to the SailorData settings. Enable "Enable OTA update of the SailorData Bridge" and tap Save. The data field will stop updating, confirming it has entered update mode. If the data field continues to update normally, tap the Save button in the mobile app a second time.

Another way of triggering update mode is to use an app like nRF Connect: Connect to "SailorData Bridge", find the characteristic which allows to Write (8ce53270-a68f-4577-b066-0bade7159b02), write the UTF8 string "OTA" and the bridge disconnects, confirming it has entered update mode.

The third way is to open the enclosure of the bridge and press the SW2 button for 1 second while the bridge is powered on. The red LED turns on once the bridge is in update mode.

Phase 3 — Upload firmware: The bridge will restart and broadcast a temporary Wi-Fi network:
Network name: SailorData-Bridge (firmware version prior 1.0 used 'N2K-BLE-BRG-UPDATE')
Password: sailordata (firmware version prior 1.0 used 'update')
Connect your phone or computer to this network. Open a browser and go to http://sailordata.local or http://192.168.4.1. Select your firmware file and confirm the upload. Do not close the browser or power off the bridge during upload — it restarts automatically when complete.

The bridge has a LED indicator that provides status information:

• Flashing Green: Bridge is receiving NMEA2000 data from the NMEA2000 network.
• Flashing Blue: Bridge is waiting for a Watch to connect.
• Solid Blue: A Watch is connected.
• Solid Red: The Bridge is in OTA mode.

Receiving NMEA2000 data (flashing green) but no Watch is connected (flashing blue):

Receiving NMEA2000 data (flashing green) and a Watch is connected (solid blue):

As the LED's on the board are super close together, it is not always easy to distinguish between the different states.

Yes, all Pro features are active after the bridge is powered on. They will stop working after 10min, unless you enter a valid license key.

Connect to the web interface of the SailorData Bridge. On the Config tab, toggle the switch to enable the NMEA to Wi-Fi router / gateway mode (Pro license feature). The bridge translates NMEA 2000 (NMEA2000) PGNs into NMEA 0183 sentences and streams them over Wi-Fi (TCP/UDP) so marine navigation apps like Navionics Boating, OpenCPN, Savvy Navvy, and iSailor can receive live GPS, AIS, wind, depth, and speed data.

• What is a polar chart?
  A polar chart (or polar diagram) defines your boat's theoretical maximum speed for various wind angles (TWA) and wind speeds (TWS). It serves as the baseline for calculating your real-time sail performance and polar efficiency percentage on your Garmin watch, helping you trim sails effectively and hit target speeds.
• How do I get polar data for my boat?
  You can find polar diagrams for many boats on websites like ORC, ORC data on github, Another site with ORC data. If your boat is not listed, you can create a custom polar chart using performance data from your own sailing experiences or by using polar prediction software.
• How do I configure polar data on the SailorData Bridge?
  Access the web interface of your SailorData Bridge and choose one of two setup methods on the Config tab:
  • Manual Entry: Enter individual TWA/TWS target speeds directly into the configuration grid.
  • CSV Upload: Upload a standard formatted .csv file using semicolon ; delimiters.
• Required CSV Format Example Your CSV file must match the matrix structure below (columns represent True Wind Speed in knots; rows represent True Wind Angle in degrees):

twa/tws;4;6;8;10;12;14;16;20;24
0;0;0;0;0;0;0;0;0;0
43.5;2.76;0;0;0;0;0;0;0;0
43.5;0;3.82;0;0;0;0;0;0;0
41.9;0;0;4.55;0;0;0;0;0;0
40;0;0;0;5;0;0;0;0;0
38.5;0;0;0;0;5.24;0;0;0;0
38.2;0;0;0;0;0;5.36;0;0;0
38;0;0;0;0;0;0;5.42;0;0
38.3;0;0;0;0;0;0;0;5.48;0
39.7;0;0;0;0;0;0;0;0;5.5
52;3.09;4.23;5.06;5.54;5.8;5.93;6;6.06;6.06
60;3.3;4.45;5.26;5.7;5.95;6.1;6.18;6.26;6.28
75;3.42;4.59;5.39;5.84;6.11;6.3;6.44;6.59;6.66
90;3.49;4.74;5.61;6.04;6.27;6.39;6.59;6.9;7.11
110;3.51;4.75;5.63;6.12;6.46;6.75;6.98;7.38;7.76
120;3.33;4.57;5.48;6.03;6.41;6.76;7.09;7.91;8.76
135;2.91;4.06;5.01;5.75;6.18;6.54;6.9;7.82;10.09
150;2.39;3.46;4.43;5.25;5.85;6.23;6.57;7.29;8.62
147.8;2.45;0;0;0;0;0;0;0;0
147.8;0;3.55;0;0;0;0;0;0;0
152.3;0;0;4.35;0;0;0;0;0;0
155.2;0;0;0;5.05;0;0;0;0;0
163;0;0;0;0;5.48;0;0;0;0
170.9;0;0;0;0;0;5.8;0;0;0

See an interactive demo here

Via the web interface of the SailorData Bridge, you can enable Victron Energy support (Victron to NMEA 2000 / NMEA2000). This allows the bridge to read data from Victron Energy devices via Bluetooth (BLE) Instant Readout and send it over the NMEA 2000 network to your chartplotters. The following data can be read from Victron Energy devices:

• Battery (e.g. SmartShunt, BMV-712): voltage, current, SOC, remaining runtime
• Solar (e.g. SmartSolar MPPT): panel voltage, yield
• Chargers (e.g. Blue Smart IP22/IP65): charging current, status
• DC converters (e.g. Orion-Tr Smart): power output

You can configure up to 4 Victron devices. Scan nearby Victron devices will list nearby devices which you can add to the bridge. You will need to enter the respective encryption key for each device. You can find the encryption key in VictronConnect → Settings → Product Info → Instant readout via Bluetooth.

See an interactive demo here

Step 1: Enable web server With SailorData running on your watch, open the Connect IQ app on your phone and navigate to the SailorData settings. Enable "Enable web server on the SailorData Bridge" and tap Save.

Step 2: Connect to the Bridge The bridge will act now as a Wi-Fi hotspot:
Network name: SailorData-Bridge
Password: sailordata
Connect your phone or computer to this network. Open a browser and go to http://sailordata.local or http://192.168.4.1. You can then use the web interface to monitor live NMEA2000 data from the NMEA2000 network, see real-time polar performance data, enable the NMEA to Wi-Fi router and/or enable the simulator.

See an interactive demo here

When you open the enclosure, you will find two buttons:

• SW1: Pressing this button will restart the bridge.
• SW2: Pressing this button will put the bridge in OTA mode.

In case you don't have access to a boat with NMEA2000 data, you can use the built-in simulator of the SailorData bridge to generate test data.

Step 1: Enable Live Monitor With SailorData running on your watch, open the Connect IQ app on your phone and navigate to the SailorData settings. Enable "Enable web server on the SailorData Bridge" and tap Save.

Step 2: Connect to the Bridge The bridge will act now as a Wi-Fi hotspot:
Network name: SailorData-Bridge
Password: sailordata
Connect your phone or computer to this network. Open a browser and go to http://sailordata.local or http://192.168.4.1. You can then use the web interface to monitor live NMEA2000 data from the NMEA2000 network and/or enable the simulator.

Step 3: Enable Simulator In the web interface, click the "Simulate NMEA2000" switch. The bridge will now generate simulated NMEA2000 data and broadcast it to your watch. It will stop processing real NMEA2000 data from the NMEA2000 network.

The bridge uses protocols and connections designed to be compatible with the NMEA2000® standard, however it is not formally certified by the National Marine Electronics Association (NMEA). "NMEA2000" is used solely to describe technical compatibility.

Because this device lacks formal NMEA2000 certification, its use within any marine network is at the user's own risk. I accept no liability for network disruptions, data errors, or damage to other connected electronics. By installing the device you acknowledge this and accept full responsibility.