Bay of Rómenna
From Tolkien Gateway

Aldarion Returns From His First Voyage by Ted Nasmith
The Bay of Rómenna was an inlet of Belegaer on the eastern side of Númenor that separated Orrostar to the north from Hyarrostar to the south. The bay had a narrow opening where it met the ocean, widened in the middle, and narrowed again at the mouth of the Firth of Rómenna.[1] Within the bay was a small isle called Tol Uinen. Prince Aldarion frequently anchored the Eämbar off of this island and lived aboard this ship due to Tar-Meneldur's coolness to his son's nautical outlook.[2]