Sorry about this but in a way it depends on your age and the company you like. You will find single group get-togethers on most cruise ships but the younger element generally go for Ocean Village etc. and older P & O. with Celebrity, Royal Caribbean, Princess and Holland America straddling the middle of that section. The more you pay the more likely you are to find, how do I put this, perhaps a more ( see I can't say "select" or "refined" ) reserved group like Cunard or Saga. Hope you get my drift because it is a great way to have a holiday with "built-in" friends ....Nei.
Fred. Olsen are pretty good for singles and have a significant number of single cabins.