A standard transatlantic crossing from the USA (typically New York City) to the UK (Southampton) takes exactly 7 nights on a dedicated ocean liner like the Queen Mary 2. Because this route involves sailing directly across the North Atlantic with no port stops, the ship travels at a higher speed than typical leisure cruises. If you choose a "repositioning cruise" on a standard cruise line (like Royal Caribbean, Norwegian, or Celebrity), the journey usually takes longer, often 12 to 15 nights, because these ships are designed for leisure and often make stops in places like the Azores, Bermuda, or Ireland along the way. Most transatlantic crossings occur in the "shoulder" seasons of April-May or September-October when cruise lines move their fleets between the Caribbean and the Mediterranean. For those looking for the classic "Golden Age" experience, the 7-day crossing remains the gold standard, providing a week of "sea days" where the focus is entirely on shipboard life, formal dinners, and crossing the vast expanse of the Atlantic without the distraction of ports.