If you go in December, there will probably be younger people!! plus its an amazing ship (freedom) that attracts the younger crowd, so i would worry.
and for october....basically the same thing. and its a 5-night cruise, and the shorter the cruise the more younger people that will be onboard.
NCL Dawn 6/21/06 Bermuda
10/30/08 X Constellation Caribbean
Costa Fortuna 3/08 Eastern Caribbean
Costa Magica 2/07 Western Caribbean
HAL Noordam 11/06 Eastern Caribbean
X Zenith 6/06 Bermuda
HAL Zuiderdam 5/05 Western Caribbean
HAL Maasdam 6/04 Canada/New England
CCL Triumph 12/03 Western Caribbean
CCL Victory 11/02 Eastern Caribbean