I've been on one cruise before, Royal Caribbean Hawaii, and planning a cruise to Alaska in 2008; we are considering Royal Caribbean and Holland America. We really enjoyed RC's activities on the last ship, especially the "ship shape" physical activities/classes during the days at sea.
My question: what on-board activities/classes do they have during port days? I've noticed that on the 7 day Alaska cruises most days are at a port, but what if we don't leave the ship all of those days? Also, how would RC differ from Holland America on these days, or would they be that much different?