Gandalf’s Possible Inaccuracy in the chapter “The Shadow of the Past”

[Zigûr]

Originally Posted by Gothmog, LoB

We also have to keep in mind that Númenóreans must have known about the existence of the Rings of Power. Three Nazgûl were Númenóreans after all, and if some of them were of the line of Elros (which is not unlikely in my opinion) then they would have known even more about them.

In Letter 211, however, Professor Tolkien does state that "I do not think Ar-Pharazôn knew anything about the One Ring. The Elves kept the matter of the Rings very secret, as long as they could. In any case Ar-Pharazôn was not in communication with them."
Of course this is the same letter in which Professor Tolkien states that Sauron had the Ring with him in Númenor, so I suppose, if you dismiss that idea, the idea that Pharazôn was ignorant of the Ring can be dismissed as well, but that borders upon dismissing too much in my opinion. In any event the Ring could have been easily hidden when he was taken prisoner, and would have looked like a piece of ordinary jewellery in any event.

I don't have a problem with Sauron having the Ring in Númenor but I do find the image of his spirit carrying it off back to Middle-earth with him rather silly.