I got a set of walkie talkies. They are about the size of a cell phone. My wife and I take them to the mall so we can get in touch when it is time to leave. She shops and I walk, so we don't stay together. We used to pick a meeting place and set a time, but this works better. I think they will be useful on a cruise ship. I can remember walking all over a ship a few times just trying to find her. They should solve that problem too. They don't replace a cell phone, but they are cheaper in the long run. Besides, we only have one cell phone. I drive and she talks, and that's the safest way to do it.

Walkie talkies are not toys. If you had a set as a kid, they probably weren't very good. You might want to look at the modern version, because they are clear and powerful. Some of them claim a range of 8 miles. Ours claims 5 miles, but if they have a good signal a mile or two away I will be happy with that.

When my kids were little they had a set of toy talkies, which were good up to about 100 yards. They developed a game called "walkie talkie hide and seek." One kid would hide and give hints about his location to the other kid. If you were "it" and the hidden person stopped giving hints, you knew you were real close. They played it for hours.
Howard