There is a kids crew program on the Norwegian Sea. 2-5 year olds and 5-10 year olds. Both will take kids from 9-12, 2-5 and 7-9. Additional night care is available for a cost.
This program seems thrown together. The newer boats like the Star have much, much, much better facilities for kids. The kids area on the Sea is in a small cabin on the 3rd floor, however, the counselors take the kids out and around the boat.
We dropped our 4 year old off and she seemed to enjoy the interaction with the other kids, however, the counselors (teenage girls) appeared very bored with their job and were not very enthusiastic.
I dropped in to check on the kids during the day and most were just sitting around. It did not seem very fun for the kids. So I took my four year old out.
It's too bad, the M/S Sea did not refurbish the kids areas. I was very impressed with the kids program on the M/S Star! In any case, the counselors should have a better program that gets the kids outside more.
Remember your kids are also on vacation!