One thing to note about Paris in December is that the sun doesn't come up until 7:30 am and it starts to get dark at 4 or 5.

It snows there too so one way to see it on an all day trip is to do the Hop on Hop Off which was very good. If I had a day and a half, I would not miss the Musee d'Orsay which you can combine with the Seine boat ride and Eiffel Tower for one day and the Hop on Hop off the other.

VOYAGER:
MC to FLL 11/07
MC/Dover 6/06
MARINER:
BCN / Ven 10/11
Alaska 2001|2006
Panama Canal 2003
NAV
Caribbean 11/06
Bermuda|New Eng/Canada 6/04
PG 5/05
OCEANIA
Nautica |Ist/Athens 6/07
Regatta|Baltics 6/08
Riviera 2013 Crossing -Istanbul to Miami