I went on an ultra-luxury cruise on Seabourn Cruises and after the first day I could not see what made it different to other "regular" cruises I had been on. But over the week I realised what ultra-luxury cruising on lines like Seabourn, Silversea Cruises, Regent Seven Seas and Ritz-Carlton is really all about - and why people so much money to go on them. It was not what I thought before I went.