Actually, after being held for years by the Cunard Lines's S.S.
Mauretania, then by a number of Italian and other British liners, the Blue Riband was retired for the USA by the S.S.
United States in 1953. She averaged something like 44 knots both ways on her maiden voyage. She had an ungodly superabundance of all-American horsepower, and her hull was classified Top Secret (still classified Secret while she lay at her pier in retirement in 1969).
And I was one of her smaller passengers on the return voyage. I have a vivid memory of a broad, foaming white wake that stretched out like a ruler to the horizon, and a raging, 40-knot gale that swept her decks as she stormed across the Atlantic.