Well, as long as you have 2, they will work in Greece too. The only issue is, they are made to work on Frequencies that are for public use in the US. Not sure if they are ok to use those same frequencies in Greece/Turkey (who knows, they may be military channels over there)
I'm not sure as to how to go about finding out if they are ok to use because I don't have a radio frequency allocation chart for those countries. And I don't know if they would provide them to me if I asked.
Your best bet would be to just rent the walkie talkies on the ship. (Most of the Carnival ships have them for rent) Ask your travel agent to find out if yours does. You could always buy the walkie talkies and take them with you, but unless you plan on using them again in the future, that might be cost prohibitive. We use ours all the time, (for more than just cruising too)
I'll check into it and see if I can find information on if the US freqs can be used in that area or not and I'll get back to you.
Everybody seems to agree that Motorola Radios seem to work very well. (click on Find at the top of the page, then type "Motorola" and search all forums) That's what I have used for 4 years and I'm very pleased with them.
Oh I agree on the Motorola radios (many because I work for Motorola... so I didn't want to appear biased.) Motorola invented the walkie talkie... nuf said... I just didn't want to tell worrywart to use the US version in Greece/Turkey without checking into what the frequencies are used for in those countries. Unfortunately, I have not been able to do so. The person I thought would know didn't. I'd hate to get someone in trouble with the local athourities. If you do bring radios from the states (which we didn't have a problem with in the Carribean) I would not bring them ashore with you and only use them on the ship. That way, with the shorter range of the radios you would not have to worry about interferring with anything. OR just get the rentals from the ship.