Two entries with the name Marine.
Marine
In Wirnt von Grafenberg’s Wigalois, a lady from Alarie.
She became a knight – one of the only female knights in Arthurian romance – after her grandfather, Count Adan of Alarie, was captured by King Roaz of Glois at a battle in Damascus. Marine collected a troop of female warriors and entered into the service of Queen Elamie.
She joined Gawain’s son Wigalois (who had rescued her grandfather) in his campaign against Prince Lion of Namur, and she was tragically killed in battle by Duke Galopear of Greece. Adan avenged her death by slaying Galopear.
Source
Wigalois | Wirnt von Grafenberg, early 13th century
Marine
Daughter of King Urien and sister of Yvain in Claris et Laris.
King Tallas of Denmark besieged her father in an attempt to marry Marine by force. Sir Laris, Arthur and his knights lifted the siege, and Marine married Laris.
Source
Claris et Laris | 1268