Split - Omis

I've been to Croatia three times but never with a car. I know having a car makes it easier to hop from place to place, but I think you have an awful lot of lodging changes planned. Since Omis is (per ViaMichelin.com) about a 40-minute drive south of Split, I'd be inclined to combine those two stops and stay in Split. You'd want to be sure you have convenient parking in Split that allows you to get on the road easily. Alternatively, you might stay in Omis (I've never been there) and day-trip back to Split.

I'm not clear on where you plan to drop the car. If you intend to take it to Brac and on to Dubrovnik, check with the rental company to be sure that will be allowed.

I hope you won't be so jetlagged you see nothing of Zagreb. It has a very picturesque, bi-level historic district. The architecture is quite different from what you'll see along the coast.

I believe you'll be able to get by with just one night at Plitvice, as long as you arrive by mid-afternoon or so--and perhaps even if you do not. I imagine four to six hours inside the park will be enough for you. I think the park sells two-day tickets that would allow you see part of the park on the day you arrive and finish up the next morning. There have been reports here that if you stay at one of the in-park hotels, it will stamp a one-day ticket for you to allow you back into the park the next day. I have never tried to verify that. The key thing is to do as much of your park exploration as you can outside of day-tripping hours. The walkways were packed when I entered the park around 11 AM (after one hour in the ticket line) back in 2015. It was not nearly as nice an experience as my earlier visits. So you need to get up early after spending the night at Plitvice and get into the park when it opens. The park now sells tickets online, and you should take care of that ahead of time.

A preliminary look at skyscanner.com suggests that non-stop flights between Dubrovnik and Athens do not operate every day of the week even in July and August. The schedule is even thinner in June. If you have to deal with connecting flights, you'll spend a lot more time in transit and probably pay a lot more money. In addition, you'll need to be sure you have a protected connection so you aren't left hanging out to dry if the first flight is delayed or canceled.

Omis is an average but pleasant enough seaside resort ruined by the bottlenecks of traffic that stream through there. As you already have lots of short stays, I would cover it as a day trip from Split. I haven’t done it, but there is kayaking there, starting up in the hills and paddling down to the coast. I have been there in June and July and it’s too hot for most activities - we have often had temperatures of 30+ degrees even at 10pm.

You need to be at Plitvice when it opens to minimise the crowds. I would drop the night at Zadar which is out of the way and add this to Zagreb.

Trogir is a pleasant half day excursion from Split.

If you are going to book an excursion, I would book direct with the operator rather than through a third party. Be prepared for long queues to get into the caves.

As has already been indicated, there aren’t many direct flights from Dubrovnik to Athens.

Omis is a small enough town that you can easily tack it on as a day trip from Split. Also, since you’re driving, I would consider Plitavice as a stop over. Get there early in the morning and then when done, head to Zadar. It’s a great stopping point between the two cities and you really only need a day at Plitavice. When I went in October I drove there from Zadar, drove back to Zadar to return the car, then hopped on a bus to Zagreb. So it’s definitely doable in a day especially if you’re not backtracking like I did. I quite liked Zadar over Split and Dubrovnik because it was much less crowded and felt a bit less like a tourist trap. It also had the best sunsets of my trip.

I would think about waiting to book your boat tour. There are a TON of companies selling these tours at the port and you could easily negotiate a better rate with a large family like yours. You might be able to even just charter a boat and do a customized tour for around the same price.

Thank you all for your input. We will plan to do Plitvice in late afternoon, spend night and again in the morning before heading to Zadar. We will plan to stay in Split 4 nights and day trip to Omis, Trogir, as well as do a boat excursion to island highlights.

I guess we'll try to find a place in Split that has car parking so that we can keep car for day trips. Looking at these options... Villa Muller Apartments, Apartment Rex Exclusive, Apartment Palace Center, Apartment Galaxino, but haven't investigated parking situation yet. Is it best to stay near Bacvice Beach, close to ferry port area in Split?

As for going to Brac, should we keep the car? Is the passenger ferry from Split to Supetar via Jadrolinija? And then is there a ferry that goes from Split to Bol via Jadrolinija, Kapetan Luka (Krilo) or Adriatic Fast Ferries? What is the car ferry from Split to Brac if we choose to go that route? How far in advance do you need to book the ferries?

Not sure if 2 nights will be enough on Brac Island. Where is the best area to stay? We want to walk along the promenade in Bol to Zlatni Rat Beach - maybe rent the paddle boat with slide thing. Other must-dos on Brac Island?
—Lovrecina Bay + fishing village of Sumartin
—Pucisca Town - Stone Masonry School
—SUP tour from Postira to Pjra Bay via Brac Adventure

Ferry from Brac (Milna) to Dubrovnik via Kapetan Luca... Is that right? And is there only 1 journey / day even in summer months? Do you recommend holding onto car till we drop in Dubrovnik? Are there car ferries from Split to Brac and Brac to Dubrovnik?

Thank you so much for your help clarifying, much appreciated!