Greek ferries are remarkably reliable during the peak travel season (May through September), acting as the "highways" of the Aegean Sea. Major companies like Blue Star Ferries and SeaJets maintain high standards of punctuality for their daily routes. However, reliability is subject to the Meltemi winds—strong northern winds that can cause smaller high-speed catamarans to be cancelled for safety reasons. In 2026, the larger, conventional "slow" ferries are considered the most reliable option because they can handle rougher seas that would ground the faster hydrofoils. It is a standard travel rule in Greece never to book a flight home on the same day you take a ferry from an island back to Athens; always leave a "buffer night" in case of weather-related delays. While mechanical failures are rare, strikes by maritime unions can occasionally shut down all ferry traffic, so it is essential to monitor local news or use apps like "Ferryhopper" for real-time status updates and cancellation notifications.