Plan your race or passage with 50 forecasts, not one.
- Plan a passage or race in your browser, with your boat and your limits for wind and sea.
- ProSail sails it through all 50 versions of the ECMWF forecast, with the tides, for every departure this week.
- See which departure stays inside your limits, what to expect, and then export the route to your plotter.
Planning a passage? See an example →
Why plan with ProSail?
Leave at the best time
Compare every departure this week side by side, and see which keeps you inside your limits, not just which is fastest.
What to expect on route
One forecast can’t tell you whether it will hold. Fifty can, “Inside your limits in 46 of 50 forecasts” is something you can make a decision on.
Brief the crew & export to GPX
The arrival window, peak wind and sea state for the crew, and the route as GPX for your chartplotter.
How it works
1Create your course
Pick your route or tap in waypoints, then choose your boat and limits.
2Compare departures
Every departure is sailed through all 50 forecasts, and the best fit is marked.
3Take the route to the boat
Course to steer leg by leg, then GPX for your plotter and a briefing for the crew.
One route is a guess. Fifty routes build a plan.
The core of ProSail is a routing engine.
Race briefings, checked against what happened.
Our call, before the start
We publish which route holds up and how sure we are, and the forecast it came from, before the race begins.
Checked after the finish
We sail the same routes through the weather that actually happened, and compare them with what the fleet did.
Fed back into the engine
Where the fleet found something the forecast couldn’t see, we say so and improve how we route.
Plan your own passage in your browser.
Enter your route, your boat and your limits, and see which departure works for you across at least 50 versions of the forecast. Access opens on 23 November, with passages first and races to follow. A companion app for iOS and Android to use on board available in Spring 2027.
Questions
How is this different from other routing apps?
Most routing gives you one route on one forecast. We run around fifty versions of the forecast and show which route holds up, how sure we are and what could change it. Then we score it against what happened.
Can I rely on a Race briefing for my own boat?
Each briefing is run for one class of boat against its polars, which we name, so your times will differ. In the software you will be able to plan with your own boat. Choose your boat’s class, and we’ll use its published polar. Set how close to it you sail. ProSail is a decision support tool, your own judgement, local knowledge and seamanship still come first of course.
How accurate is it?
We publish a race briefing before each big race and an honest review after it. In the 2026 Middle Sea Race our three routes finished within 13 minutes of each other, as we called it, but the fleet found time close to land that our forecast was too coarse to see. Since then the engine includes the critical stretch near land with a sharper model where available, and we tell you if the detail is still weak. Read the Rolex Middle Sea Race 2026 review →
Is there an app?
The browser-based planning app opens on 23 November, with passage routing first. A companion app for iOS and Android, which re-checks the plan at sea, follows in spring 2027. Join the waitlist →