PredictWind Offshore Weather vs WindCalc

The Offshore App allows you to seamlessly download multiple GRIB files for your coastal and offshore passages. Quickly download and view GRIB files, weather routes, GMDSS maps and text forecasts, AIS data and satellite imagery. Access all the world’s top ranking forecast models for reliable and accurate weather data, including ECMWF, SPIRE, UKMO, GFS and more. Our very own PWG & PWE models offer incredible accuracy and a record-breaking 1km resolution. In addition to forecasts, the Offshore App also provides a suite of powerful marine tools to save you time and keep you safe at sea. Weather Routing and Departure Planning is calculated in the PredictWind cloud at the highest resolution. The finished route is then sent back to your boat in an incredibly small file size which is ideal for low bandwidth satellite and SSB connections. The Offshore App works with Wi-Fi, mobile networks, and most satellite connections using an Iridium GO!, Globalstar or Optimizer device. ADDITIONAL FEATURES GRIB file viewer: High resolution forecasts maps with animated streamlines, wind barbs or arrows. Tables: The ultimate dashboard for detailed analysis. Graphs: Compare multiple parameters at the same time. GMDSS Forecasts: View either in the traditional text format or on a map. Destination Spot Forecast: Know exactly what the weather is doing at your destination. Live Observations: Know what’s happening right now out on the water. Ocean Data: See what’s happening under the waves with ocean and tidal currents, and sea temperature. GPS Tracking: Get a free customised GPS tracking page for your blog or website. AIS Data: View over 280,000 vessels worldwide on the AIS network.

This app converts apparent wind to true wind or ground wind, depending on the inputs for vessel speed and heading. This is a computation needed daily by sailing vessels underway and by ships reporting weather to national agencies. Use SOG and COG from the GPS for speed and heading to get the "true wind" used in official forecasts (sometimes called "ground wind") or use true heading derived from compass heading and knotmeter speed to get the" true wind" used on sailboat’s polar diagrams (sometimes called "water wind). Likewise this app does the reverse computation, true wind to apparent wind, so a mariner can forecast expected apparent wind based on a forecasted true wind change and known true wind boat speeds from a polar diagram. This allows mariners to plan for the sails needed and the courses available to them when the new wind appears. The app is designed with a simple, clean interface for efficient use.