I was on the Explorer in April and the cruise was loaded with kids! I did not think this would be the case but as it turns out, it was a school holiday in the Boston area. I overheard one crew member saying they had seven hundred kids on board which is seven times the average.
As far as karaoke, I think it was every other night. I made the top nine finalists and got to sing in The Palace which is a 1300 seat room, it was pretty cool even though I didn't win.
If there was a second or third prize, I think I would have walked away with something.
Carnival Victory, 2003
Carnival Victory, 2004
RCI Explorer of the Seas, 2009
RCI Explorer of the Seas, January 2010