When visiting Naples, Sorrento, Capri, the Amalfi Coast and Salerno you should definitely allow a bit more budget for traveling by ferry. These are not the smaller water taxis, which run shorter distances on small open cockpit boats from one town to the next, but rather are much larger, more stable boats that carry people from Naples all the way around the Amalfi Peninsula to Salerno. You can plan a trip around these ferries, staying in Naples for a few days, then Sorrento for a couple of nights, then a week on the Amalfi Coast towns in a villa high above the sea. The ferries are convenient, fast (very fast with the hydrofoils, but at a higher cost) and leave virtually every hour. You can leave from Naples and arrive in Capri in 1 hour 20 minutes, or cut that down to 50 minutes with a hydrofoil. Most coast towns have ferry ticket kiosks at their port.