While you can technically buy tickets at the pier if space is available, it is strongly recommended to buy Aran Island ferry tickets in advance, especially during the peak season from May to September. The ferries to Inis Mór, Inis Meáin, and Inis Oírr have strictly limited passenger capacities for safety, and popular sailing times—such as the 10:00 AM departures from Rossaveel or Doolin—frequently sell out days in advance. In 2026, booking online not only guarantees your seat but often provides a small discount compared to the "walk-up" price. Furthermore, if you are taking the dedicated shuttle bus from Galway City to the Rossaveel terminal, those bus seats must be booked at least 12 hours in advance to ensure the ferry operator can accommodate the number of passengers arriving from the city. If you are traveling in a group of ten or more, advance booking is mandatory to secure group rates. For travelers on a tight schedule, having a pre-booked QR code on your phone allows for a much faster boarding process and eliminates the stress of being left on the pier during the busy Irish summer.