Welcome to Cruise-Chat!
The Pride is my favorite ship. Have not sailed out of Baltimore though. For Nassau I can highly recommend Blue Lagoon Island
for a do it yourself excursion. I don't know what the water temps would be in December though. They also have the dolphin and sea lion encounters.
macmom111 makes an excellent point and gives sage advice about avoiding the water taxis in Nassau. I was just there 2 weeks ago, and they looked more "rickety" than before. These are the little "barges" outside the Nassau terminal offering rides over to Paradise Island/Atlantis. If you go over, just take a regular taxi for $4 per person and be safe!