Everytime we cruise we always get to the embarkation port at least two days before the cruise. Sometimes we have a mini land vacation and make it a longer pre-cruise stay. When I see the delays and cancellations in the US now, I am thankful I don't have a cruise booked. Even in Europe, immigration delays at airports for incoming passengers are really delaying passengers. If you have a connection in a European city you really need to plan a longer layover for your connecting flight.
However, Virgin Voyages, the newest Richard Branson cruise ship has sent this to all it's passengers:
Virgin Voyages Brilliant Lady is coming to the west coast next summer. I have a friend who is booked on her out of Vancouver to Alaska. Way to go Richard Branson!

