We arrived in London the day before shp departure. Coming from the USA it's a good idea to come,at the very least, the day before the ship's departure. One never knows, flight delays, cancellations, etc. The only problem is R/C will not issue transfers unless you arrive the day of ship's departure. My travel agent and I made calls to R/C but they were steadfast concerning that policy. Can't understand why. So we had to rent a car and drive to the port. Last year we sailed Italy and the Greek Islands. We arrived in Rome 5 days prior to sail date and had no problem with Princess about a transfer to the port. They simply gave us the time to meet at the airport and voila we were transported to the ship.
Embarkation was quick and we were on the ship within 20 min.
The ship is beautiful and well kept.