florentin wrote: What types of activities are available for young people on a cruise.  Say, for a 12 year old boy? What would they do? Is it even a good idea to bring young people along?

A 12 your old boy will have a blast on a cruise. I've been cruising with Carnival and Royal Caribbean and they both have youth clubs with a lot of activities for the kids.

All cruise lines have a Youth service.
 Some involve on board activities such as swimmng, volleyball, inside games, movies etc. Some have SCUBA for kids when they stop at port, some cruise lines do day hikes when they dock  at port
Carnival Cruise C club for youth. Here is a fine example of what Carnival has.

Taking your kids on a cruise with you is always an excellent idea. Even if your on a      second honeymoon, so they get an a-joining room. julie

You'll enjoy more if you travel with friends or family members. You can bring along your kids. They will surely enjoy the activities such as going to the beach, shopping, watching shows, enjoy the pool and etc. There are cruise that provides Kids cooking demonstrations and magic shows. For sure you're kids love it.

thank you for the replies and the input

Is Disney still doing cruises on The Big Red Boat?

That would be the ideal cruise for a family, IMHO.

I was on a cruise a few years ago and noticed that my friends son did nothing but play on his gameboy the entire trip. I was totally surprised that he didn't make the kid to do something.