Hi Amanda. There's lots to do for older teens on the cruise ships. Me and 3 friends went for our graduation trip 2 years ago on the Elation (we were 18 & 19) and went again this past summer on the Ecstacy. 18 and older are allowed into the clubs, no problem. The thing I enjoy the most on the cruises is the dancing they offer almost every night. Just be sure to do as many things as you can while on the ship, before you know it the trip will be over. Its a great time, so enjoy yourself as much as possible.
Yes, lots for teenagers to do. They open the night club for teens from 9 until 10pm. All the nightly shows were fun for the teens too. They can play ping pong, shuffleboard and they have organized games for them too. Just fun to let them go and explore on their own. There is very little mischief they can get into and they can eat all day free which is the best part. My teenagers spent a lot of time in the pizzeria.
I am an older teen myself, and there was lots to do when I went on my cruise this past July. The arcade, tanning, pool games, eating, dance classes, shows to watch, and mingling with other passengers were more than enough to pass time during the days at sea. At night, the Clubs are opened, and if you're 18 and older you can go into the "Adult" clubs, but the guards won't let anyone younger in (even with parents taking you). They insist that if you want to go clubbing, then go to the 'teen' club, which the only bad thing about this was that many younger people were here, starting at about 9 years of age, and the same CD was played over and over again, which was all rap with the same beat. A lot of the older teenagers hung around outside the discos.
My 16 year old and her friend were able to get in anywhere on the Imagination three years ago, though they were not able to order alcohol drinks on the ship. They went to the adult clubs and were not turned away. They were also able to get into the R-rated late night comedy shows by going in a little late and laying low. As far as "activities" for them, they felt too old for the "teen" activities planned by carnival and went out on their own and met new friends. They had a great time just planning their own time and activities. Watch out if you will be in any port of call at night...I found out months after the fact that mine snuck off the ship in Cozumel at night and went to the bars!! There is no legal drinking age there. Don't let them have their own room!!! Have fun...good luck!