London has multiple port options within 90 minutes. Of these, Southampton is by far the port with the most options.
Cruises can be as short as a quick 2 night getaway to France or as long as a full 100+ night world cruise. On average, London has longer cruises than most other ports with more cruises being 8+ nights than 7 or fewer.
Northern Europe is the most common itinerary type and makes up over half of the options, including cruises to the Norwegian coast, the Baltic, and Iceland. There is a wide variety in length, with essentially all lasting between 2 and 28 nights.
Southern Europe is the second most offered region and are mostly 1 to 3 weeks long, with a handful on each side of that range.
World cruise options are more common here than almost anywhere else. Southampton is also one end of a semi-regular transatlantic sailing to New York in addition to the seasonal repositioning cruises.