OpenCPN

Configuration Defaults

Weather Routing Plugin

Current defaults (1.18.3)

Basic offers Quick, Standard and Professional, in that order. Quick is the hardened Original contour engine; Standard was previously called Quick, and Professional was Main. A first installation without saved defaults selects Quick. Existing routes and last-used defaults keep their algorithm and values.

All three engines remember their own tuning, shoreline resolution and GRIB cache preference. Advanced displays only the selected engine’s controls. Reset engine to preset has an Apply/Cancel preview and resets only search tuning, preserving safety, weather, boat and memory settings.

Quick/Standard start at a nominal three-hour step and 10-degree headings; Professional starts at one hour, 10 degrees and 100% effort. The permitted wind-angle range starts at 40–160 degrees; Max Diverted Course is 120 degrees. True/apparent wind limits start at 50 knots, Max Swell at 20 metres, Detect Land is enabled, and currents/motor are disabled. Review these limits for your boat.

Intermediate GSHHG is initially selected. Crude, Low and Intermediate are bundled; High and Full can be installed from Shoreline data. Chart/depth enforcement requires a compatible host and is off on first installation. Do not disable land detection merely to obtain a completed route.

Quick requires current coverage when currents are enabled, and wave coverage when a GRIB-based wave limit is active. Max Swell zero deliberately disables that limit. Quick rejects endpoints inside the selected shoreline margin; there is no implicit harbour-margin waiver. Search previews are not accepted sailing tracks: only a completed, independently validated route is accepted.

On 64-bit systems the preferred timeline cache is 2,048 MiB per engine; memory admission reduces the effective allowance where necessary. Search and weather caches are separate, and are not a total OpenCPN memory limit.

Historical example setup

The following describes older bundled examples, not current factory defaults.

Examples require suitable polars, complete weather coverage and valid endpoints. Completion is not guaranteed merely by retaining default settings.
If you are learning at this point and want to run the Examples, don’t change the configuration defaults.

Basic Tab

  1. All of these settings are set "out of the box" for the first Compute.

  2. Don’t tough anything.

Start Position

  1. Make Weather Route Position by right-click in Opencpn on the chart and select "Weather Route position"

  2. Select Start Position by selection from the dropdown.

Start Time

  1. Select Start Date & Time -User Selection

  2. Must within the grib file time window unless climatology is working too.

  3. Two options Grib Time and Current Time

End Position

  1. Make Weather Route Position by right-click in Opencpn on the chart and select "Weather Route position"

  2. Select Start Position by selection from the dropdown.

Time Step

  1. Intially this is set to 12 hours to have a fast calculation.

  2. Select between 30 min and 12 hours.

  3. For routing failures first try setting this for a shorter time step.

Boat

  1. Boat.xml path - For startup examples, select plugins\weather_routing\boats\Boat-Climatology.xml

  2. Boat.xml edit - View and get familiar with this interface.

    1. In Boat-Climatology.xml 4 Sample Polar files have been added.

    2. Highlight one of the Polars and select from the Tabs (Plot, Cross Over and Stats)

    3. At the bottom select how to view the polar True/Apparent, etc.

    4. In the Right menu select Edit to see how Editing a polar works.

    5. Close or Save this menu.

Constraints - Defaults

  1. Max Diverted Course 76 degrees

  2. Max True Wind 100 knots

  3. Max Apparent Wind 100 knots

  4. Max Swell 20 meters

Options - Defaults

  1. Time step: 1 hour 0 min 0 sec

  2. Detect Land: Checked (when first starting, uncheck it, requires High Res GSHHS)

  3. Detect Boundary: Unchecked

  4. Currents: Unchecked

  5. Optimize tacking: Unchecked

Data Source - Defaults

  1. Default Examples

    1. The wind data source used for these examples is Climatology.

    2. Climatology must be installed and enabled.

  2. For your own use

    1. Download a fresh grib of the entire route area (a little larger than then route), making sure that it is for a big enough time interval.

    2. Then set the Grib_pi at least one frame later than the start time.

    3. Grib Unchecked - You will need to check this.

    4. Climatology - Leave disabled or enabled depending..

      1. Use Climatology alone.

      2. Use Climatology (30 year Noaa data averages) to extend long trip calcs both at the start and finish.

      3. When data sources change there will be a color indication.

  3. Last Valid if Data Deficient - Uncheck. If your grib file is not long enough checking this can help.

Advanced Tab

  1. Generally the default constraints work well.

  2. These constraints speed up calculations.

  3. Some adjustments may be necessary if a route does not complete.

  4. However first decrease Time Step and increase Max Diverted Course

Constraints - Defaults

  1. Max Latitude: 90 degrees

  2. Wind vs Current: 0 (disabled) Factor for waves and hobby horsing

  3. Max Course Angle: 180 degrees

  4. Max Search Angle: 120 degrees

  5. Cyclones Avoid Crossing Cyclone Tracks: Unchecked (Climatology needed)

    1. within X months X days: within 1 month 0 days

Options - Defaults

  1. Inverted Regions: Unchecked

  2. Integrator: Newton

  3. Anchoring: Unchecked

  4. Wind Strength: 100 percent

  5. Tacking Time: 0 (disabled)

  6. Safety Margin from land: 0 nm

  7. Courses Relative to True Wind:

    1. From 0 degrees to 180 degrees

    2. by 5 degrees steps

If you are having trouble, set the Configuration to these defaults or select Configuration > Reset all Advanced: