Thanks for the reply. We (and our luggage) have to be off the cruise ship by 9am. We considered storing the luggage (3 pieces) near the dock and doing more sightseeing but the logistics started getting too complicated.
I like the idea of checking the luggage and then using the metro but DH doesn't like taking chances - we've had close calls before with strikes/accidents on public transportation. I may talk him into it once we're at the airport. Thanks!