The 2025 Atlantic Crossing series Webinar 1: Mastering PredictWind for Offshore Crossings was recorded on the 18th September 2025.
📺 Watch the Recording
You can now watch the full session on YouTube here:
👉 YouTube Recording – 2025 Atlantic Crossing Part 1
This webinar explored how to leverage PredictWind’s powerful tools to optimise your passage, including:
Introduction to the PredictWind App and Website
Weather Models & Weather Routing
Features overview: AI Polars, Wave Routing, GMDSS Maps, Extreme Weather Warnings, and Currents Maps
ECMWF Long Range Forecast: how this 30-day outlook has been improved
Practical strategies for safer, more efficient offshore passages
Below, we answer the 10 most commonly asked questions:
What is the difference between the PredictWind App / Website and the Offshore App?
There are multiple ways you can view a PredictWind forecast:
The PredictWind Website https://forecast.predictwind.com/ is used on your PC/ Mac using a web browser like Chrome or Safari. You need complete internet services to use this. It is location-based, i.e. you add your location, and we generate a forecast for that spot. This is our primary platform for subscription management, billing, and setting boat polars.
The PredictWind App is installed on your mobile device and is an online tool. It requires a Wi-Fi or cellular connection to view the forecast. It is location-based, i.e. you add your location, and we generate a forecast for that spot.
You can use the PredictWind Offshore App on PC, Mac, Apple or Android devices. It is an offline tool for downloading compressed GRIB file weather data and weather routing via an internet or cellular connection, at sea via satellite, like the Iridium GO! or GO exec. It stores files locally on the device to review offline.
What are Boat Polars, and how do I configure them?
Polars describe your boat speed and wind angle in any given wind speed.
Setting the polars in your PredictWind account is essential for an accurate weather route. Please set up the polars in your account before using the weather routing and departure planning tool on any PredictWind platform.
Relevant article: How to Set Up Boat Polars - All Platforms.
How do I set up and use Wave Polars?
With PredictWind Weather Routing, you can set your Wave Polar not only to define the performance of your boat in various wave conditions but also to view the Roll, Vertical accelerations and Slamming Incidence that your boat will experience through the route.
Relevant article: Weather Routing using Wave Polars.
Can I get more information on the sail crossover feature?
Sail Crossover Charts are visual tools that show the best sail choice for different combinations of true wind angle (TWA) and true wind speed (TWS). They are custom-built for your boat, starting from a suggested template, and let you map out the conditions where each sail works best. The sail crossover charts highlight overlapping zones where more than one sail could be used, helping remove the guesswork when deciding between options (for example, Code Zero vs A2). They are particularly valuable for offshore passages, where sail changes are more complex and resource-intensive.
Relevant article: How to use Sail Crossover Charts charts
What do all the symbols and abbreviations mean?
On the PredictWind website, PredictWind App and Offshore App, there are many acronyms, codes and symbols used in forecasts and routing (e.g. TWS, TWD, TWA, SOG, COG). This article helps explain what all of them mean so you can read the data properly.
Relevant article: What do all the abbreviations and symbols mean?
What is Climate Data (Pilot Charts), and how can they help me?
Climate Data provides ten years of rolling averages, month-by-month, for wind, wave, and weather conditions at any location using historical ECMWF data. This helps you see what “typical” conditions are like in different months, and pick the best time of year for passages or adventures. Sailing in season is key for a safe passage.
Relevant article: How to use Climate Data on the PredictWind Website
Can I get more information on the features of GMDSS/ Extreme Weather Warnings?
PredictWind uses Extreme Weather Warnings to alert you when forecast conditions meet thresholds for things like strong gusts, rain squalls, thunderstorms, etc. These warnings are displayed on maps, in routing tables, etc., so you can see at a glance where there might be dangerous or uncomfortable weather.
The text forecasts are analysed in the PredictWind cloud, and then each weather system, front, and warning region is plotted accurately on the map, providing a world-first, global view of the GMDSS forecast.
Relevant article: AI-Generated GMDSS Maps.
What is CAPE, and how can I predict severe weather?
CAPE (Convective Available Potential Energy) is basically fuel for thunderstorms—it measures how unstable the atmosphere is and gives an idea of the potential for thunderous activity not shown in the Wind Maps . It’s not a guarantee of a storm, but if CAPE is high, combined with other indicators like precipitation, it suggests a greater risk.
Relevant article: What does CAPE mean?
What is the difference between departure planning and weather routing?
In short, use departure planning to analyse which day is best to leave, then switch to weather routing to get a detailed breakdown of your passage.
Departure Planning: helps you choose when to depart by comparing options for leaving on different days or times of the day (usually Day 1, Day 2, Day 3, Day 4). It summarises the expected conditions along the route for each departure date (wind, waves, currents, CAPE, rain etc.), so you can pick a departure date that avoids worst conditions or optimizes comfort/safety.
Weather Routing: Calculates a route between two points using forecast data, giving a clear picture of what conditions to expect along the way.
It draws on multiple high-resolution forecast models, allowing you to compare outcomes and see how different scenarios may unfold.
The routing also includes wave and current data. By entering your boat’s details, you can view additional metrics, such as roll, vertical acceleration, and slamming, to better understand your comfort levels.
Each route provides summary statistics for wind, waves, currents, rain, CAPE, and any extreme weather warnings, helping you plan passages with a realistic view of the conditions.
Why should I get a Professional Subscription to PredictWind?
The Professional package gives you access to the best data that PredictWind has to offer. The Professional level allows access to the following:
High-resolution forecast GRIB files (1km and 8km PWG/PWE, 9km ECMWF, 27km GFS, 14km, 10km UKMO)
Ocean current GRIBs (Mercator and RTOFS)
Sea Surface Temperature (SST).
High-resolution tidal currents
Wave modelling of your boat (including Roll, Vertical accelerations and Slamming Incidence). Please learn more with this 1-minute video.
AIS data in the Offshore App, accessible via satellite when offshore. Please learn more with this 1-minute video.
AI Polar generation
Any weather route or departure plan calculation using either the Standard or Professional Subscriptions will consider your choice of ocean current data and wave polars when calculating a route. However, only the Professional Subscription will show you these details when viewing the results in the tables and along the route.
🌐 Want to Learn More?
Explore the PredictWind Marine Meteorology Course with in-depth articles, visual guides, and expert tips. Of particular importance for the East West Atlantic crossing will be the Clouds article.