Bonaire has no useful public bus network, so a rental vehicle is the practical choice beyond central Kralendijk. Divers often choose a pickup for tanks and wet gear. Drive on the right, keep speeds down around donkeys, goats, cyclists, and rough road edges, and do not leave valuables visible at isolated shore entries.
Ordinary cars handle the paved north and south loops, but Washington-Slagbaai has rough, unpaved roads and rental agreements differ on which vehicles may enter. Check both the park rules and your contract before going. Taxis work for airport and dinner trips but become expensive for a full island circuit; fares are set rather than metered, so agree the amount first.
Kralendijk is compact enough to walk. Cycling works around town and on quieter roads, though heat, trade wind, and limited shoulders make longer rides more demanding than the flat map suggests.