le Pont desouz Ewe, le Pont Perdue; le Pont Sous Aigue, - Leue; le Ponz Souz Aive, Lost Bridge, Water Bridge
The Underwater Bridge was also called the Lost Bridge, and was so called because it ran under the surface, with as much water above it as below. Chrétien describes it as only a foot and a half wide, and equally thick. It rather clearly equates with the Vulgate's "pont desouz ewe".
Having traveled some way together in pursuit of Meliagrant (Meleagaunce) and Guenevere, Lancelot and Gawaine learned of the two bridges from the Damsel of the Crossroads. Pressed by Lancelot to choose first, Gawaine finally declared for the Underwater Bridge. Even though, like Lancelot, he left his horse and more cumbersome arms on the other side, he was to fall in and nearly drowned.
Chrétien does not detail Gawaine's adventures on his way to the Water Bridge, saying only that they had been many, hard, and perilous. While they may also have consumed an inordinate number of days, the length of time Lancelot had already spent on the Gore side of the bridges before Gawaine was found creates the impression that the latter knight must have bobbed about in the water for quite a while before his rescue. His apparent long survival in the water may give further evidence of the otherwordly nature of Bademagu's Gore.
Pont Irois and Pont Norgalois | The Legend of King Arthur