Ditch the rental car?

Take the ferry from Korcula Town to Orebić, on the Pelasac Peninsula. The ferry (a quick trip) runs several times a day, more in high season. I didn't actually drive it; I took the bus from Dubrovnik to Korcula, and it uses that same ferry.

I know how to get from Split to Korcula island by car ferry (to Vela Luka) but not how to get from Hvar to Korcula directly, unless the coastal ferry has started running again a few times a week? Or have you found a car ferry directly from Hvar to Korcula? The passenger-only catamaran would definitely make that connection easier.

I suppose you could take the ferry from Split to Korcula and day trip to Hvar by catamaran from Korcula, and leave the car in Korcula. I seem to recall that catamaran service would allow such a day trip that way.

I have a similar problem to yours.... We are travelling to Croatia in June (for 4 weeks) and most of the time, especially for the 2 weeks that we are in Dubrovnik and Cavtat, we will not be using a Hire car (there is a really good bus & Water Taxi service) but then we are taking the Catamaran Ferry to Hvar Island and will spend a week there and there seems no easy way to hire a car on the Island ... unless we take a ferry to Split, collect a car and take it back to Hvar for a few days - then Car ferry back to Split! All of which seems to be a big waste of money!

It seems that when travelling on the islands one has to compromise... its easier & cheaper to travel without a car, but a car does make it easier to get around when on the islands! There are local busses (and we will have to use them on Hvar island) but they don't seem to run that often..

But from what I can make out, you can take a Car Ferry from Split to Hvar (Stari Grad - which is where we are staying, looks great!) ... spend a few days there or in Hvar Town - then on the day you leave, travel to the far end on Hvar island to Sucuraj, where you can take a Car Ferry to the Mainland (just a short way). Then drive down to Ston and onto the Peljasac Peninsula, and travel down to Orebic - from there you can take a Car Ferry to Korcula.

From Korcula to Dubrovnik, you may need to go back this way .... and then carry on down to Dubrovnik. But I am not entirely sure there are not other Car Ferries (Korcula- Dubrovnik)
But yes, cars do seem to be a liability on the islands and around the Old Towns (they are all pedestrian only) so you would need to park the car for quite a lot of the time.

So I agree, it seems to be a toss-up!

In May 2014 I did a similar trip. I ditched the rental car in Split, took the ferry to Hvar, stayed 2 nights, then the ferry to Korcula, 2 nights there, and then another ferry to Dubrovnik, where I stayed 3 nights.

This worked out great for me. I rented a scooter one day in Hvar and enjoyed exploring the island that way. I didn't miss the car on the islands, and I was certainly glad not to have it in Dubrovnik.

I don't know what to suggest in terms of the other explorations you might be able to do with a car, but I think you will be able to enjoy yourselves without a car when you're visiting the islands and in Dubrovnik.

So in summary: the only reason you'd really want/need to keep the car after Split would be to explore the Pelasac Peninsula...and maybe to explore the islands beyond the towns, if you have time. FYI, if you really just want to drive through and see the Pelasac Peninsula scenery out your window, you can take the bus from Korcula to Dubrovnik (instead of taking a catamaran or ferry) and you'll drive right through it. Could be an early bus at the crack of dawn, though.