In case the complication is not working properly, first of all update the app and be sure to have at least 3.30.

Then check in the settings page of the app on the Watch:

• is the configuration in Beaufort scale or Speed?
  • check the configuration in the settings page inside the app on the Watch
• is the location/city configured correctly?
  • try to change the City, even if it is correct. If the change doesn't work, update the Location settings:
    • Open System Settings on your iPhone
    • Privacy, Location, Waterspeed
    • Change the value to any other value and then back to "While using..."
    • Restart the Watch
• is the Watch connected to Internet?