Contact Verizon about this. I recently read they are making changes that could be beneficial for data users. As someone else said, the options could be better closer to when you take your trip.
Be sure to call the GLOBAL people. Anyone who answers the general number is not likely to give you correct answers. Trust me. This is the voice of experience. And be sure to talk to them about the time you will be on the ship. I have also read that using your phone on board for anything is outrageously expensive, so you will want to combine what you learn from Verizon with what you learn by talking to the cruise people.
We have added Verizon travel packages to our phones since 2009. We have used them in all the countries you mentioned. We always use Wi-Fi where we stay. It's ubiquitous these days. We occasionally use it in ordinary cafes. Many have it there. We have religiously avoided using data due to the cost, but the possibility of Verizon making it reasonable is definitely of interest to me and I'll check that out before our next trip. From what I read, you have to have a 4G phone to get that option.
We use our Verizon android Moto X phones a lot, have set up Wi-Fi hotspots using them and subscribe to 10 gigs of data per month. I'm hoping that by the time we take our next trip, using that data (which we pay for whether or not we use it) will be possible overseas, either by using our phones as Wi-Fi hotspots or mainlining it.