How to activate and basic usage of Theyr weather on iNavx -- Plus limitations, and blank parameters screen

Article IX14302, June 30, 2015

As long as a Theyr Weather subscription is present and activated on an account, the iNavX app has a Theyr menu inviting one to pick a forecast region and forecast model type. Once selected, the weather graphics semi-transparently overlay chart graphics at a regional level.


Purchasing Theyr

At the Fugawi Store's Charts section for Theyr compatible with iNavX, purchase the subscription type you prefer.


Calling up a Theyr Weather forecast in iNavX 5

1. Select a chart at a broad regional scale; whatever the bounds you define on the screen are the approximate bounds of the weather forecast about to be fetched. Vector charts cleared of super-detailed chart elements may be preferrable for the final resultant weather forecast graphics.

2. Tap the More tab (bottom-right corner, beneath chart shown in regular / non-full-screen mode). Then tap Theyr Weather.


More tab of iNavX leading to Theyr Weather


3. Tap Region to bring up a selection screen.

4. Select a forecast region appropriate for the geographic range of the current chart region. Notes on the regions:

  • Global Forecast 0.5 degree (or 1.0 degree) is the most dependable selection in that it covers everything that can be forecast for.
  • The second North America selection is for Doppler Weather Radar NEXRAD historical data (usually about ~30 to ~60 minutes old).
  • Northwest Europe is the only forecast region that includes Tidal Stream data.
  • The model titled South America is not literally all of the continent, it is actually a modest sized area near Uruguay, extending from about 30º to 39º South latitude.


Selecting a regional model


5. Select the type of forecast (varies by region selection). The most popular forecast type is Wind / Pressure / Precipitation.


Theyr Type of forecast selected


6. Select the Chart tab again. After several seconds, a graphical overlay of weather forecast data appears. The double-arrow-circle icon in the upper-right animates the frames of data.

You may need to slightly pan and zoom about to trigger the weather graphics display. Other overlay data (ex. Waterway Guide data layers) may suppress the weather forecast graphics or delay their appearance.


Theyr Forecast seen on Caribbean chart in iNavX


7. To dismiss the weather, tap the date & time title bar and, when the Theyr dialog appears, tap Done. Alternatively, tap the spoked-wheel icon for Settings and deliberately select the forecast region as None.


IMPORTANT... data delivery limitation:

The app fetches and holds in memory one weather forecast at a time. Once you fetch a new weather forecast, the previous one is erased. If you are deep out in the ocean and have no Internet connection, you will be unable to get a different weather forecast or extend the geographic range of the existing forecast.


Legacy instructions from iNavX 4.7


After subscribing to a Theyr Weather service at, go to the iNavX app. View any chart, then tap the Forecast tab | Theyr Weather Parameters. If the screen is blank except for a Brightness adjuster then that means the app is not able to see a spare / open Theyr subscription on your X-Traverse account.

Blank Theyr Parameters screen due to no subscription

Assuming a Theyr subscription is found, it will get activated automatically. Then two dial pick wheels appear.

From the top dial select an appropriate region. Note that some region names are highly generalized: "South America" really covers only an area around Uruguay and a little of Argentina. A thick red rectangle appears around regionalized coverage areas. To avoid confusion, you may wish to stay with one of the Global Forecast models which cover nearly everything on the Earth's surface.

From the bottom dial, select a type of weather forecast from what is available in the list. Some regional models have more or have less forecast types than others, that's normal.

Selecting Global Forecast 0.5 for Theyr Parameters

After selecting a region and forecast type, return to the chart. After a brief downloading time, weather graphics overlay the chart area in view.

Before and After showing zoomed out chart and Theyr overlay

Legends superimposed over the chart indicate which color corresponds to which magnitude of temperature, precipitation, etc. Wind is shown in a standard set of symbols with short barbs = +5 knots, long barbs = +10 knots, combinations of 5 and 10 barbs, and a 50 knot triangle barb.

Another example of Theyr Parameters selected for NEXRAD

Only the North America (second) forecast model shows NEXRADD doppler weather radar data -- which is not a forecast about future weather, rather it is data of what has happened in the recent past, sometimes as often as 30 minutes old.