I am not a fan of cruise ship transfers, so my advice would be on arrival to use:
SAS Transport Quality Shuttle Service at Affordable Prices
. They are the most resonable @ $15.00 pp. We always use them. By the time you get your luggage and board their van, you should be arriving at the ship in time to board, eat lunch and relax,and explore the ship.
On the way back I agree with Dave, do a ships post excursion. This way the ship worries about your luggage, not you,and you get to extend your trip a bit, in plenty of time to get you to the airport, without the being in the rush of most cruisers leaving late morning /early afternoon.
Any more questions please ask, we are ready to help...oh. btw..did you get travel insurance?