Euskotren operates a train from San Sebastián to Arcachon hourly. Tickets cost $2 - $4 and the journey takes 32 min. 2 other operators also service this route. Alternatively, Eurolines FR operates a bus from San Sebastián to Arcachon once daily. Tickets cost $55 - $80 and the journey takes 2 h 30 min. Ouibus also services this route 6 times a week.
How to get from San Sebastián to Arcachon
From Loiola-Donostia train to Hendaye, train to Facture Biganos, then train to Arcachon. 4 h 6 min 46€. From San Sebastián bus to Bordeaux, walk to Bordeaux Centre, then bus to Arcachon. 4 h 42 min 58€. From San Sebastián drive to Arcachon. 2 h 14 min 31€.