Given its small size and proximity to Ischia, Procida is an excellent day trip. You can visit the island of Procida by taking one of the many ferries that depart from Ischia Porto, or by booking a private boat with or without skipper.
Visiting Procida from Ischia
Ferries run from Ischia to Procida all year round, primarily because many routes begin in Naples or Pozzuoli and stop first at Procida and then at Ischia and vice versa on the return trip. On Procida, ferries dock at the Marina Grande port, and it's easy to get around on foot or via one of the island buses as the entire area of the island is only 4 kilometers and it is quite flat.
Otherwise, you can rent a scooter at the port to move around the island faster.
A One-Day Itinerary to Visit Procida from Ischia
From the port, walk about 20 minutes to Terra Murata, the historic heart of Procida that sits slightly higher than the rest of the island so its ancient inhabitants could watch the horizon and defend themselves from attack. Here, visit the former Bourbon prison (book a visit via the Comune di Ischia website) and stroll through the historic center to the San Michele Arcangelo Abbey.
From here, take the long staircase down to the Corricella harbor, a tiny fishermen's village of colorful houses crowded together, the most famous sight on the island of Procida. This is the best spot to stop for lunch, and there are a number of restaurants with tables directly on the pier.
Afterwards, relax on the Chiaia or Postino beaches before heading back to Ischia.