You would most likely find other cruising with you by posting on the "meet on board". There is also a special message board just for teens, you should check that out as well. If your into chatting there is also a teen chat every Sunday evening at 8:00EST.
Is this your first cruise? Here is a link to the teen section here at cruisemates too, enjoy:
My wifer and I will be going on the SOS on the Feb 11-15 sailing (and very mush looking forward to it). We will be leaving the kids home on this cruise but aill be taking them on a cruise during the summer (they will be 12 and 18 at the time). I hear that SOS has a great kids and teens program.