Capri is not far from Positano, and it only takes about 40 minutes to reach the island by boat. During the summer months, there is a ferry that runs between Positano and Capri in addition to a number of boat tours.
This is the most popular and least expensive type of tour. Small-group tours set sail from Spiaggia Grande in Positano via boats that can fit up to 20 passengers. The route to Capri passes the Li Galli Islets before circling the island to take in the Faraglioni before docking in Marina Grande. Once docked, passengers have a few hours of free time to sightsee on Capri before heading back to Positano in the late afternoon.
There are a number of types of boats for a private boat tour with skipper from Positano to Capri, including traditional wooden gozzo boats of various sizes, speedboats, and yachts. Private tours can depart from the main pier in Positano or from other agreed-upon locations nearby, including private hotel or villa jetties, or the piers in Praiano, Maiori, Minori, or Amalfi.
Most private tours last all day, though you can also book a 4-hour tour that does not include free time on land to explore Capri.