hi, i am a teen who has been on this before. personally i thought it was awsome. the catamaran that they rent off the island is awsome, you can just sit on the cargo net and watch the scenery, water, or participate in the activities. there is always soo much to do. i was with a group that didnt want to do anything, they main guy ended up having to give up because no one wanted to participate in anything, but being the center of attention i like to be all the time, i got things going a little and it was cool.
as for space, i was able to sign up like 1 day into the cruise, as not many people were on the list. i dont know if i got lucky or what but thats how i got on.
other activities i reccomend are the night dances, they may seem boring on the first night, because no one dances, because no one knows each other, but as the cruise progresses, they get poppin!(lol, j/k) another one i did, was the teen adventure thing on
castaway cay, now that was tite, umm....i mean awsome! you get to do soo much, snorkeling before anyone else even gets to step on the island, biking, rafting, hiking, its all cool. just remember to stay in the rope side, and dont go into the submarine while snorkeling, as i got busted, and yelled at. well, now that i talked your head off, go off and enjoy your cruise! tell your teen to get involved all the time, they wont regret it! and also be prepared for early morning arrivals, meaning, if they do participate and like it, they wont be coming home till about 2/3 oclock in the morning. lol have fun, i envy you!