The Croatian islands are close together on a map and farther apart on a timetable. Ferries are commuting infrastructure in the morning and a tourism product by July. A good hopping trip uses two or three islands, not six, and treats the catamaran as a reserved seat rather than a bus you can always catch.
A clean route for a first visit: Split as the hinge, then Hvar or Brač, then Korčula or Vis, then back. Split has the flights, the old town, and the port. Do not spend your only evening there in a rush to leave. One night on arrival steadies the luggage. Each island after that deserves two nights if you want a swim that is not immediately followed by a ticket queue.
Foot passengers and cars
If you are walking on and off, the fast catamarans are your friend and they sell out on summer weekends. Buy the ticket when the hotel is confirmed. If you are taking a car, you are on different, slower ships, and the car reservation is the constraint. Many old island towns do not want the car in the center anyway. For a week of swims and dinners, foot passenger plus a taxi from the port is the lighter trip. Rent a car only for an island where you truly intend to reach a beach the bus ignores.
Check the port name. “Hvar” can mean the town or a different landing on the island depending on the vessel. “Split” has more than one waterfront mood, but the ferry port is specific. Build forty minutes between “we should leave the apartment” and “the gangway goes up.” Boarding closes earlier than travelers from train countries expect.
Where to sleep
Book rooms with a flexible rate for the first and last nights, and be stricter in the middle islands you most want. August in Hvar town is a seller’s market. June and September keep the sea warm enough and the ferries honest. If a sailing is cancelled for weather, the next one may be tomorrow. That is why two nights beats a connection that has to work at 16:10 exactly.