There is nothing quite like waking up somewhere new without ever having packed a bag twice. A cruise turns travel itself into the destination: you unpack once, and the world arrives at your window, one port at a time. Santorini one morning, a quiet fjord the next, all while your cabin, your favourite spot on deck and your evening dinner reservation stay exactly where you left them.It is also one of the most sociable ways to see the world, and one of the most private, often at the same time. You can spend the afternoon in a lecture on Byzantine history or in complete silence on a sun lounger with the sea going by, and nobody will think twice about either choice.