“She was the fairest treasure of the Maidenvault. Lord Oakenfist the great admiral lost his heart to her, though he was married to another. She gave their son the bastard name of ‘Waters’ in honor of his father, and he grew to be a great knight, as did his own son, who put the ‘Long’ before the ‘Waters’ so men might know that he was not basely born himself.”
— A Feast for Crows, Jaime I
“I know that tale as well, but Daeron made too much of it in that vainglorious book of his. Ships won that war, not goat tracks. Oakenfist broke the Planky Town and swept halfway up the Greenblood whilst the main Dornish strength was engaged in the Prince’s Pass.” Stannis drummed his fingers on the map.
— A Dance With Dragons, Jon IV
There are two mentions of Alyn in the main series. I suppose it’s interesting that these two things are what Alyn is best remembered for in Westeros: his enduring love for Princess Elaena and his victory during the Second Conquest of Dorne.