You will love it. They have many activities that are age specific like clubs and such so you should have lots of fun. If you are into boogie boarding or surfing you will really love the Flow Rider
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Radiance Of The Seas-07
Adventure Of The Seas-05
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My wife and I just got back 3 weeks ago from Freedom of the Seas. As a teenager there are plenty of things for you to do. At least the teens at our table had a great time. Their parents hardly saw them during the day with all the activities they have. Arcade, Flowrunner, and Teen get-togethers. You will NOT be bored.
There's a LOT to do for kids your age on the ship. Since everyone is only there for a week they make friends fast and hang out together.
I was on FOS last week with my two sons, roughly same age as you. I saw them maybe 3 times during the whole cruise. Given a choice between returning to Disneyworld/Universal or the FOS again next year and they chose the ship.