Eastern Europe Cruise - changing money for multiple currencies, or can we use the Euro?

[LSWRArt]

We are doing a trip from Romania, through Bulgaria, Serbia and Croatia to Hungary.  None use the Euro and each country has a different currency.  We will need a sensible amount of money in Romania and Hungary, but what do we do in Bulgaria, Serbia and Croatia?

We will go on the organised tours, but we might want a drink, or an ice cream.  I assume too small to use a credit card.  Are Euros accepted at local cafes, etc., or will we have to change money into each currency and quite possibly not use it?  

The holiday costs enough without wasting money en route, so any suggestions welcome.  

Thanks, Arthur

[pmatawan]

Although you may find merchants who accept Euro, you will likely need local currency..... although you will find credit cards accepted everywhere, even for a small purchase. I use a Schwab debit card for atm access to get local currency. They reimburse atm fees anywhere in the world. I opened a Schwab checking account for the sole purpose of international travel.

[caradara]

We did a river cruise Bucharest to Budapest and changed money in the beginning and end since we were in hotels and needed to pay for meals.  The other stops we only needed cash to tip the guides and bus drivers (your choice) and we used leftover money from Bucharest.  It's not ideal but we couldn't change money for such small tips.  Hopefully they receive enough to make it worth their while to do the currency exchange.

[MSUjohn]

Change?

ATM, let your bank know your itinerary. 

[ColdCruise]

We did a Danube cruise in March-April, Bucharest->Hungary. I loaded a prepaid debit card with money, card didn’t charge foreign transaction fees. Took cash out in Bucharest about 200usd worth and it covered expenses for 4 days with plenty left over, I  pre booked and prepaid tours by locals for local trips before the cruise, (definitely recommend Liviu for Bucharest-Brasov-Bran Castle-Sigishoara area). During the cruise, a lot of places took euro and almost everyone took credit. I used the prepaid credit card when possible having been warned by a travel safety service not to use my regular cards. In Hungary I took out about 100 usd cash from the prepaid and that was enough for casual money for 3 days and the prepaid for meals Gave the excess lei and florint to a charity at the OTP airport. 
also I’d recommend downloading Bolt on your phone for use instead of taxis if you need a ride. Hungary doesn’t have Uber, but Bolt is similar and available in Romania and Hungary. We used uber to get from Bucharest to the port, big savings over ships transfer and since we were doing our own thing anyway, it was convenient as heck.

enjoy your trip!