Rent a car if you want to see more than Willemstad and the beaches nearest the city. Bandabou in the west and Bandariba in the east are both easy driving loops, but their sights are too spread out for useful beach-hopping by bus. A small ordinary car is enough for the main roads.
Traffic drives on the right. At unsigned crossings and roundabouts, vehicles coming from the right have priority; through traffic has priority at a T-junction. Road surfaces vary, signs can be easy to miss, and goats wander onto rural roads. Do not leave bags or dive gear visible in a parked car, especially at quiet beaches.
Large buses, called konvoi, run from terminals in Punda and Otrobanda. Minibuses with BUS on the number plate cover shorter routes without a fixed timetable. They are cheap but awkward for beach-hopping, particularly later in the day. Taxis have no meters, so agree the fare before setting off. Curaçao has no Uber or Lyft.
There is no scheduled passenger ferry to Aruba or Bonaire. Inter-island travellers normally fly.