"Der Taucher" (The Diver) is a ballad by Friedrich Schiller, written in 1797, the year of his friendly ballad competition with Goethe.
Der Taucher Wikipedia
A king throws a golden beaker in an abyss and promises that the one who can recover it can also keep it. But none of his knights and knaves wants to do it. So the king has to ask three times before a Edelknecht (squire) finds his courage. He deposits his sword and his coat and commends his life to god and jumps in a suitable moment into the intimidating sea. Everyone at the shore frightens that the boy will not return. After a while he emerges with the beaker in his hand. His terrifying report intrigues the king and he wants him to dive again and promises him a precious ring. The king's daughter tries to convince her father to stop with his cruel demands. Yet the king throws the beaker in the sea again and promises now, that the Edelknecht become a knight and will marry his daughter, if he recovers the beaker again. The boy has a look at the girl and wants her to become his bride, so he jumps into the deep and does not return.
Franz Schubert set "Der Taucher" as a song for bass and piano in two versions (1813–1815, D 77 – the second version originally D 111).