The plugin also requires Boat performance data (polar data). There are many Polar Data files built in and included as a part of the plugin. Also Polar Data can be developed from:

Note: Boat performance data should be in a format compatible with weather_routing_pi. The plugin will convert the file to a format it can use (fixing certain minor variations and irregularities) or declare it unusable.

Note: Grib data is predictive data, and as such it will be subject to change. Generally data past 3-4 days it is unreliable, and the longest grib available is 16 days (with a larger time interval between data points). For longer voyages, Climatology_pi data can be used as an alternative data source to extend the routing calculations.

Cuba to Puerto Rico,title="Irma Cuba to Puerto Rico"]]

Example: Routing from Cuba to Puerto Rico through Hurricane Irma.(Don’t ever do this!) Showing Grib_pi “Weather Data” (Right Click on Chart) and Weather_routing View > Report & View > Plot.

Weather Routing is a deep plugin which can use three other plugins concurrently, so stick to basics when starting out.

You need to activate OpenGL in order to have the route display on top of the grib layer!

https://github.com/seandepagnier/weather_routing_pi

Weather Routing

Weather_routing is remarkably flexible, but with that comes complexity. New users must not dive in changing settings without understanding what they are doing or how it affects “Computation”.

Please follow this tutorial carefully and you will succeed the first time. Once you get familiar with the interface and have had successes, learn all the features gradually, changing and adjusting one setting at a time.

Grib_pi is installed with OpenCPN. Learn how to use it and download a fresh Grib file with wind, current & waves.

Climatology_pi should be installed as directed.

Climatology NOAA 30 year average Wind and Current data in September near Cape Lookout

Climatology Configuration of Wind Roses (Size=100 and Spacing=50 is good too.)

Download and install to improve routing with “Detect Land” checked.

If you are working with Land Interface a lot, this is not optional! Best to install it.

You must Configure weather_routing to match your sound judgment and realistic goals. You are in control, use your own judgement when you review the results. This cannot be emphasized enough. Weather_Routing_pi is just a tool in your hands, you are in control.

If the plugin is downloaded and installed, with default settings unchanged (or “Reset All” is used), the plugin should create an optimized weather routing with just a few specific additional settings and “computation”.

Weather_routing_pi uses [Boat].xml files to store multiple [Polar].pol, *.csv or *.txt filenames which are used with the Current ”Configuration”. Also the [Boat].xml file can be “Save as Boat” to another boat filename such as Boat-Test.xml or [Your-Boat-Medium-Wind-Heavy-Sea-Clean-Bottom].xml.

Many new users have have trouble “Completing” Weather Route Configurations due to Polar:Fail messages, which is often because the single polar they have used only has TWS from 6-20 knots and does not span the entire true wind speed range of the particular grib file being used.

To help new users when starting out, we will create a Boat-test.xml file that references three “polar-xx-xxx-x-xx.pol” files which cover a full TWS (True Wind Speed) range of 0-60 knots. The Weather_routing Configuration will utilize the best polar information from the multiple polar files in Boat-test.xml after computing the “Sail/Polar Crossover” calculations between the different polar files being used.

Three Boat.xml zipped files

unzip to C:\ProgramData\opencpn\plugins\weather_routing\boat which are preconfigured files that should work with the Polar and WeatherRoutingConfiguration.XML file downloads. These files are the same as Weather_Routing_Setup above.

Later on, after some successful weather routings, users are encouraged to create separate boat performance [polar].pol files for:

Example of useful Polars for your boat:

Using the sails normally used for each type of wind, such that the full range of True Wind Speed (TWS) is represented (0-60 knots).

Polars-Pol.zip

Please Download, unzip and copy the six .pol files listed below into your data\polars directory. For Windows use: C:\ProgramData\opencpn\plugins\weather_routing\data\polars These files are the same as *https://opencpn.org/wiki/dokuwiki/doku.php?id=opencpn:opencpn_user_manual:toolbar_buttons:plugins:weather:weather_routing#weather_routing_setup[Weather_Routing_Setup] above.

Three Stepped Range TWS Files used together (use either Sail or Power for TWS-0-6)

Single File with Full Range TWS 0-60 knots

[Boat].xml files are normally located here for Windows: C:\ProgramData\opencpn\plugins\weather_routing

In Boat.xml Menu Edit please Add these files

Use of these three files will cover a wide wind range from 0-60 knots (with 0-6 under power). If you just want to use one file for TWS 0-60 knots use Test-TWS-0-20+60.pol.

Once the three files have been added, next pick Save as Boat then type Boat-Test and “Save” to create and save “Boat-Test.xml”

Now when Computing “new” Configurations first check the configuration by selecting Boat-Test.xml at the Boat section “….” just ahead of “Edit” in the “Configuration” Menu. Once that completes properly, then create a “Boat.xml” file for your boat with reference to your normal boat polars and use that.

In the Configuration Menu after “Compute”, a message will show to the right of the Configuration.

“Complete” affirms that the computations completed. “Fail” indicates they did not and that some setup parameter may be out of range. The failure messages have been made to be more descriptive to help.

If your polar doesn’t include boat speeds:

There are many reasons a Computation cannot complete, or fail. The computation is dependent on:

Different Time Intervals - Everything Else is the same.

Beginners should first try a simple route, with starting point and end point, 5 degree steps, and possibly a 3 hour time interval until they see it is working. The time interval depends on the speed of the boat and distance traveled, grib file downloaded.

Provides setup flexibility for various factors:

Configuration and Edit Boat.xml,title="WR Configuration and Edit Boat.xml",width=600]]

Boat position (round circle) is when stepping through the grib file (assuming you use a grib file and not climatology of course).

Moreover, if multiple routes are computed and shown (selected), when stepping through the grib the boat position is shown simultaneously on each route.

that: when you step through the grib you will see the boat position at that current grib time (not “the multipier of the two time intervals”). This can be right on an isochrone or between two isochrones (if grib interval is smaller than wxrte time interval).

The Route Manager can be used for listing the weather route. Right click a weather route and pick “Properties”. Also a Weather Routing can be Exported to a gpx file or saved to a Route in Route Manager.

In addition to “Standard actions” Weather_Routing_pi will work with other Plugins

Weather Routing will use two grib files that are loaded by Grib_pi. This is useful when you have downloaded a GFS Wind and Pressure Grib, and an RTOFS Current Grib of similar time period and resolution. First Load two Grib Files Concurrently (Wind + Current) in Grib_pi. Then in WR Configuration check the Currents box.

In this Baltic Sea example there is an underlying current file with black arrows and the area of the grib is shown in light read. The wind
pressure grib is shown with brown arrows with feathers.

Create Boundaries recognized by Weather_Routing_pi. Useful for guiding routing.

Red hatched Boundary along the Nova Scotia coast was created in Ocpn_Draw and used in weather_routing, to prevent routing in that area.

Red hatched Boundary created with Ocpn_Draw and used in Weather Routing Configuration > Options > Basic Tab > Check “Detect Boundary”

(anchor, boundary, speed, course, deadman, NMEA etc.)

Set various parameters (range in meters, degrees, time in seconds or minutes, speed etc.)

about this and refer to the default list in this manual above. Or download the Weather_Routing_Setup above, install it again and start over.

It is most likely that the routing did not reach the destination. -Understand that the routing ends if destination is inside two isochrones, which is likely what you have, but remember between these two isochrones the boat can only move in straight lines and if there’s land in the way, the destination could be unreachable. Islands and Harbors are very prone to this kind of issue.

Try a new destination (or start) well outside of the harbor. This issue occurs at both the start and the finish when the routing is tends to be near land with islands, harbors and complex shorelines, or try shortening the interval.

Try uninstalling the weather_routing plugin and removing all files and configuration from the system as outlined in the manual then re-install and make a new configuration. Now you should see a red circle moving along the route as you step thru the Grib file.

When you step through the grib you will see the boat position at that current grib time. This can be right on an isochrone or between two isochrones (if grib interval is smaller than wxrte time interval).

Grib data Time Interval: Available in 3,6 and 12 hour intervals. Weather_Routing Time Interval: Often set to a smaller interval, say 3 or 1 hour intervals. But sometimes to complete to the destination the interval has to be set considerably smaller, say 10 minutes. Weather_routing will then interpolate the Grib file interval down to 10 minutes. When you try to step through the grib file to understand the conditions on the routing, you will jump across the interpolated isochrones. This is determined by the weatherrouting time interval.

For example: From the WeatherRoutingConfiguration results the arrival time is 21:33, for a departure at 12:00. This means a duration of 9 hours, or three grib intervals of 3 hours. Consistent with the 3 steps in grib controller (3 hour time intervals). If you have weather_routing time interval set to 10 minutes, the boat will skip over 18 isochrones for each step of the grib controller.

View > Settings “Alternates for all isochrones” is unchecked and there are still black alternate routes showing. How do I eliminate them? Set alternate route thickness to “0” on the View > Settings menu.

Create a new position with the same name to replace it. There is then a prompt to overwrite the old location. This works from the context menu on the chart also.

Weather_routing is only as good as the data provided by the Grib plugin and the Climatology plugin.

The weather routes created may not consider or “see” normal navigation considerations and issues, therefore every route should be checked very carefully for navigation markers, shallow depths, bad currents, rocks, land and other obstacles and hazards.

Stelian wrote:

In fact, the paths in WeatherRoutingConfig.xml and the boat XML files need to be there, because they tell the plugin where to find the corresponding boat/polar files. And since there might be several boat or polar names with the same name (but located in different folders), the paths need to tell which one is to be used.

However, there is one exception to this: at the packaging time, we don’t know where the files will be installed - we know we want to put these in the user directory (ProgramData), but this path is dynamic, it depends on the user name (in case of multiuser systems). For example, on Linux, it might be /home/stelian/.opencpn/plugins/… or /home/rick!

So what we’ve done is to change the code to allow the config file to use name without the path. The plugin, when it tries to open the file and if there is no path before, will automatically append the user directory path. This is why the xml files containing the default configuration need to have only the filenames and not the paths inside.

Moreover, the files can contain the path to the contours. This path, once again, is dependent on the user. So we’ve just removed the CrossOverContours from the boat xml files, and made sure that the plugin will regenerate the contours upon start.

For the date problems, well, we simply noticed in the XML file that the dates were in mm/dd/yy format, so I’ve just modified them to yyyy-mm-dd, (if you had saved the files using the current version of the plugin this should have been done automatically).

There was an hour issue too, the file had 09:00 (local time I suppose), I put 00:00:00 instead, I don’t think it matters much anyway for such long routes.

I also renamed a boat.XML file to .xml (notice case), it’s more standard that way (I know that windows doesn’t care much, but on the other systems the conventions are quite strong).