Translation added, along with a transcription of the original text for future reference.
With that thought, she became a pirate, adventuring upon the seven seas. Crossing the raging ocean, the hidden treasures of the many islands she reached were all terribly beautiful.However, no matter how beautiful the hidden treasures were, they were not the thing that she was searching for."A very beautiful thing it must have been."For future reference, here is the transcription of the original text:
「とても美しいものだった気がする」
そう思った彼女は
海賊になって、七つの海を冒険した
荒れ狂う海をこえて
たどりついた島々に隠された財宝は
どれも大変美しかった
しかし、どんなに美しい
財宝のなかにも
彼女が探す物はなかった