Just wanted to weigh in with my experiences and thoughts about the Vibe Teen club. To each their own, of course.
First off, we traveled with my family and my sister's family. We have two boys, 14 and 15. They have two girls, 13 and 16. My nieces are more shy and my sons are more outgoing, so we wanted all four to be able to be together, to have fun together, and to look out for each other. We had no problem getting the 13-year-old into Vibe. My sons told me there were more than 50 teens in Vibe that first night for the ice-breakers, but I guess that wasn't over the limit. I asked my 13 year-old niece at the end of the cruise if the older kids gave her a hard time, and she said they didn't, but she had three people she knew to help her out, too.
They all liked Vibe very much. They enjoyed many of the scheduled activities like Zombified, Gender Wars, etc. They ate all their meals with us and did all the excursions we did, and for the most part when to all the main shows that we did, as well as hanging out with us or just with their cousins at various times on the ship. So we saw them plenty and enjoyed good family time. But there were plenty of times they wanted to go off to Vibe and that was fine too. It gave us a great chance to be alone as the adults and enjoy the many adult activities on the ships. (There are really great adult spaces and activities!) Vibe activities ran until 1AM each night, and though we never let them stay 'til then, they did stay out later than we might have let them stay out in other venues back home. Plus it was good practice for them to have to break away at the time we designated and and "come home." Only once did we have to come get them (because they didn't come home on time), and when we got to the outer doors of Vibe, there they were, in the process of leaving.
As for safety, I have several thoughts, that come from my experience with the ship, and my outlook in general. Just my opinion.
The first is, the ship is MUCH safer than a city. Completely safe? No. Of course not. Nothing is. It is much smaller than a city. Much fewer people than a city, and a greater percentage of them are families trying to have a vacation, so a smaller chance of danger. Plus there are way more crew and cast members looking out for the guests, and the kids especially. We told the kids not to go into any stateroom other than ours, not to bring others to our cabins, and we have had lots of frank conversations about sex and drugs and laid out our specific expectations for them. Could they still do it? Sure. But I think it is less likely than back home, and certainly less likely than some unfamiliar city.
One other thought that I haven't seen expressed much on these boards when people are talking about their kids (teens especially) is the benefits of letting kids learn independence and responsibility through the opportunity to practice it. As a parent, I want my sons to learn to make good choices and behave responsibly, and to do that, they need chances to TRY that. I don't want to just throw them out and say "good luck." So when a somewhat sheltered, lower-risk opportunity comes up for them to practice being responsible, I jump at it. It is great for them developmentally. I also was very clear that this freedom I was giving them was on a trial basis, and that if they wish it to continue they must use it wisely.
One other thing, given that kids are kids, and hormones are hormones, I submit to you for consideration that Vibe might be the BEST place for your teens to be when they are out of your sight during the cruise. My sons told me that the counselors had strict rules about PDA (Public Displays of Affection) and enforced those rules pretty strictly. (The counselors were more lax about the no cursing rules, but reigned that in some.) So there weren't make out sessions (or worse) in the Vibe spaces or during the Vibe activities. However, on the last full day, at
Castaway Cay, my 15-year-old son and I were swimming in the water on the beach and we observed a group of about 10 teens (8 boys, 2 girls) standing in the calm waters. They were (apparently) playing some sort of truth or dare, that culminated in 9 people trying to convince this one girl to make out with this one boy, and then counting a certain number of seconds before they could stop. (And then restarting the countdown, etc.) My son whispered to me that all those kids were from Vibe. If they had been in Vibe at that moment (or with their parents) they wouldn't have been participating in that heavy duty peer pressure.
React to that as you wish. Even that isn't sex or drugs, but maybe not what you'd want for your kids on vacation, or maybe exactly what they'd be doing at home. I don't know.
I just know that for my sons and my nieces, Vibe was a fun time, and a good mix between safety and freedom. I know it gave my shy nieces a chance to assert themselves and feel good about their self-confidence, and it gave my sons a chance to practice good choices and observe the choices of others. That, to me, made Vibe a good experience for my family.