San Antonio is compact and walkable in the centre. To reach the beaches to the west — Cala Bassa, Cala Conta, Cala Salada — you need transport. Scooter rental is straightforward and cheap; most beach access roads are narrow enough that scooters are actually more practical than cars in high season. Bicycles work for the flat coastal roads, less so for the hillier inland routes.
Water taxis run from the port to Cala Bassa and Cala Conta throughout the summer and are the most enjoyable way to reach those beaches — no parking stress, and you arrive by sea. Public buses cover the main roads to Ibiza Town (frequent) and some beach areas, though the service is not always convenient for the western coves.