Precursor of vessels to come, Sovereign of the Seas was the largest cruise ship afloat when it was introduced in 1988. Two sister ships followed, and, although they all share the same layout, subtle differences exist in size and the number of passengers they carry. Sovereign received a major refurbishment in late 2004, with the addition of a new Miami Beach-style Latin club, and a Johnny Rockets diner. Other improvements include an expanded spa and enlarged areas for children and teens. Balconies were also added to 62 junior suites.