My husband and I are renting a car to do a month long tour of Croatia, Bosnia and Slovenia in June. In RS' book he indicates that you cannot reserve a space for the car ferry ahead of time. Yet on the the ferry site, you can indeed buy tickets for the dates we want to sail. Are you only buying a ticket and not actually getting a guarantee of getting on the ferry? Anybody recommend buying tickets now or the day of travel?? Thanks for any advice in this.
It depends where you are starting from. If getting on in Dubrovnik, Split, or Hvar, then yes, you should be able to get a ticket in advance, with a car, it is a bit more work. But Korcula is just across a narrow stait from Orebic on the mainland with a local ferry that runs nearly constantly, with no advance tickets.
Until last year, you couldn't buy tickets for car ferries in advance. You can now, but all they do is permit you to travel on the day that you have booked. You cannot buy a ticket for a specific timed ferry.
There isn't much benefit of buying in advance, as you still have to join the queue with everybody else and wait your turn. Saturday crossings are usually busier. I have only once not got on the Split to Stari Grad ferry. You just have to walk into town and have lunch or sightsee and get the next ferry.
The ticket booths take cash or credit cards and in my experience all speak English.
The ferry space is limited and you are NOT guaranteed a reserved space on the ferry. This is because rather than parking spaces, they just jam in as many cars as possible. If there happen to be large trucks, they will of course fill up multiple spaces while tiny cars will allow more cars on the ferry. So, they don't know how many cars will fit until they start loading cars onto the ferry. It is probably easiest to buy the ticket on the day of travel or 1 day prior to the day of travel, especially if the ferry is in the morning. Even with the ticket, you will want to show up early enough to the ferry port to make sure you're not at the end of the line, and possibly denied a spot. In that case, you just have to wait around for the next ferry.