For those worried about your 13 year olds being with 17 year olds, relax.
We have taken a teen twice and after the first evening ice breaker games to get aquainted both times the younger teens just naturally hung out together as did the older ones.
16 and 17 year olds DON'T want to hang with 13, 14 and 15 year olds. It is just natural for them to separate, plus counselors have always been in The Stack any time it is open. They interact with the kids all the time.
They do lots of cool things with the kids, scavenger hunts and brains verses brawn , dances, smoothie and pizza parties, movies etc...
Our teen was a grandaughter, and she loved it and we saw her many times with her new friends, they were all the young ones. She said the older teens go hang around the pool and chow down pizza or the guys seem to hang around the video games all the time. She never had a problem with the older kids and never saw anyone experiencing a problem.
I'm sure your teens will be the same way, the younger ones will just naturally hang out together, especially when they meet other teens on this thread. They will be in a small group, safety innumbers.
Now if this was the Carnival Glory I would say put a chain on them for safety

,
Kathy