steph, post a request for a cruise out of Texas in the Bargain Finder's section of this board. You will be contacted by reputable TA's with great prices, avoiding airfare maybe.
As for the teens, most of them end up just hanging out with eachother, somehow,someway they always manage to find one another, must be some sort of teen radar. Our teens didn't do the teen activites, they did take advantage of the computer games in the teen center, the took part in the sports and games, hung out at the pools and hot tubs.