Das verratene Meer (The Betrayed Sea) is an opera in two parts and 14 scenes, with music by Hans Werner Henze to a German libretto by Hans-Ulrich Treichel, after Yukio Mishima's novel The Sailor Who Fell from Grace with the Sea (Japanese: 午後の曳航, romanized: Gogo no eiko).

Composed between 1986 and 1989, it was Henze's ninth opera, his third that he wrote for the Deutsche Oper Berlin.

It was first performed at the Deutsche Oper Berlin on 5 May 1990, when it was conducted by Markus Stenz and produced by Götz Friedrich.

It was also the national premiere of this opera, it was conducted by Kazuyoshi Akiyama.

For the first time, the opera was performed in Japanese language and with an all-Japanese cast.