Flights from East Italy to Split Croatia?

Is there a seaplane or puddle jumping service that can be hired to
make this trip?

No

Often people assume that Italy and Croatia are well connected. They are not.

Out of the low cost carriers, Easyjet flies to Split from Venice, Naples and Milan while Volotea offers flights from Bari, Bergamo, Palermo and Venice. I’m not sure exactly where you mean by “East Italy” as the eastern Adriatic coast is very long but I would be surprised if none of those flights offered competitive fares this far out. Just make sure to read the fine print regarding check-in, baggage etc.

Alitalia and Croatia serve Rome Fiumicino, but those flights are likely to be more expensive. If transfer time is not an issue, Dubrovnik and Zadar airports are worth checking, too. Each airport’s respective Wikipedia page has a list of all airlines serving the airport and their destinations.

What is "East Italy"? If you could provide the actual city, that would be helpful.

We're traveling with a group to Bari and then breaking off to head North to Venice. So we'll be on the Adriatic side. It's probably as close as I will ever get to Split.

So you want to go from Venice to Split? Is that right? Are you trying to fly one-way or will you need to return to Venice or somewhere else to fly back home?

I was hoping to fly from Bari to Split, then bus up the Croatian coast to a ferry city to get to Venice. Or maybe fly both legs. Unfortunately Volotea does not appear to have any Bari/ Split flights in June.

Do you have a week for the whole trip or just for the Croatia leg?

We’ll be in Bari for four days with a group then we’ll have six days to travel before returning home. Venice is a “must-see” destination, (our daughter insists on seeing Venice - she will not be happy if we go to Italy and skip Venice) so we can’t get too far from the Adriatic. I’d like to venture to Split but we don’t have nine hours to spare for a ferry ride.

Well, it is going to take most of one day to get to Split and most of a second day to get from Split back to Venice. These are long distances. I think you should dismiss the idea of Croatia until you have more time.

• Jadrolinija ferries run overnight from Bari to Dubrovnik three nights/week in June, usually Thursday, Saturday, and Sunday. Their ferries from Ancona to Split usually depart on Monday, Wednesday, and Friday evenings in June.
• Volotea flies nonstop from Bari to Dubrovnik (not to Split) on Wednesdays in June.
• Rome has the most flight options to Croatia, especially outside of peak season.