Many people use walkie-talkies on the ships. If you're interested, you can look up some of the many previous discussions on this topic. Go to "Find" above your name on this thread, and in the drop-down menu, enter walkie-talkies, and UNcheck the option to search "this forum only." You'll find some interesting information and perspectives on their use.
I think Walkie talkies are a good tool. However I also think they can be irritating. On one of our cruises kids were running wild yelling into the walkie talkie ect.
Walkie Talkies serve a purpose, but should not be baby sitters.
I use to take them with all the time, and had very good ones...but most of the time they didn't work that great because of all the electronics on the ship....they worked much better on shore...and now with the BIG ships, I'm sure they will not work even more.....Happy sailing....