From Cork, take the N71 towards Bandon and Skibbereen. Keep on this road until you reach Skibbereen and from here follow the signs for Baltimore (R595). In Baltimore village, you can park right beside the pier from which the ferry to Cape Clear departs, but it is not unusual for the car park to be full so allow some extra time to find alternative parking.
From Cork City, the only option is to take Bus Eireann service 237 (Timetable) to Skibbereen and change there for a service to Baltimore. The latter bus service connects with most sailings to Cape Clear. The 237 also serves Schull, but only one or two services do so every day. Keep in mind that there are no services between Skibbereen and Baltimore on Sundays and Bank Holidays and it is necessary to arrange for a taxi or lift to Skibbereen or Baltimore.
The ferry to Cape Clear departs from from Baltimore and Schull