We will be flying into London next September to take a cruise from Southampton. We'd like to do some sightseeing first, perhaps to see Brighton Palace or Dover cliffs, castle and WWII tunnels. When we first fly in, should we stay 1 night in London to sleep and then head south or go directly (from the US in Coach seats-yuck) south? Where should our base town in the south be? (We have been to London many times and don't need to sightsee there this trip.) Thank you.
Whenever taking a cruise, you should fly in a day or two earlier to minimize any problems. You might be better served flying into Gatwick 2 days early and staying at a local airport hotel or closeby. Then, rent a car at the airport terminal and head south for your day trip.
You can get from Gatwick Airport to Southampton in just under 2 hours by train and the fare's around $45. A taxi can take you to the ship. See: http://www.nationalrail.co.uk/