My DD was 10 on our last cruise and didn't have sign out priveleges. She is now 11 and I don't think I would do it this year if we were sailing, I don't let her go to the mall alone so feel there is probably more people on the ship than at the mall. Someone stated in an older post awhile back that the ship is a floating city with 2,000 people.
Joanna - contrary to the majority on this thread, I agree with you completely. When we go on any non-cruise vacation, my son isn't granted any more or less priviledges than while onboard ship. And those priviledges do not extend to signing himself out of the protection offered by the lab.
It is not a matter of my son's common sense or ability to handle responsibility. It is the 2500 other passengers of which only ONE is required to be left-or-right of civilized society to affect his life and, consequently, my life, forever. NOTHING is worth that risk. When he is older, more mature and capable of better defending himself against an adult, then he will have the freedom to sign out of the Lab at his own discretion.
Also, on our first cruise I came across a number of tweens as well as teens who probably were "perfect angels" around their parents but acted like imperfect devils when in the company of kids their own age. I know, it's never YOUR children. It's always OTHER children and sometimes THOSE children instigate yours.
Anyway, I view
DCL as a FAMILY vacation and am glad my son WANTS to spend time with Daddy (and, I should add, Grandma). Soon enough he'll be embarking on his own life's adventures anyway, so I treasure now our time together as a family...