Will my ferry sail? Wind and departure-ban risk

When strong winds are forecast, the port authority can suspend departures (the απαγορευτικό απόπλου). The general criterion depends on the ship's length, so a large ferry may sail while a small boat or a high-speed craft stays in port.

Choose your route, ship type, day and departure time. The tool reads the forecast at several sea points along the route and shows the strongest wind and highest waves you are likely to meet.

We fetch the hourly 10-metre wind, gusts and significant wave height from the free Open-Meteo forecast and marine APIs at 3–5 sea points on the route, and keep the worst value each hour. Wind speed is converted to the Beaufort scale.

We check the hours from one hour before departure until the typical arrival time. For conventional passenger ships, the general departure-suspension criterion by overall length is 6 Beaufort up to 25 m, 7 Beaufort from 25 to 40 m, 8 Beaufort from 40 to 75 m and 9 Beaufort over 75 m. Risk is "High" at or above the criterion and "Medium" one Beaufort below it.

High-speed craft are judged on the significant wave height in their operating licence. If you know it, enter it and the tool compares the forecast waves with it; otherwise it uses an indicative 7 Beaufort.

Piraeus – Paros on a 130 m ferry, leaving at 07:00: if the strongest forecast wind on the route is 8 Beaufort at 10:00 near Syros, the risk is "Medium" because the criterion for ships over 75 m is 9 Beaufort. The same forecast gives "High" for a 35 m ship.