YOU SAID:
ze dolf in the water.
INTO JAPANESE
彼女は水の中に潜っています。
BACK INTO ENGLISH
She is diving into the water.
INTO JAPANESE
彼女は水の中に飛び込んでいます。
BACK INTO ENGLISH
She is jumping into the water.
INTO JAPANESE
彼女は水に飛び込んでいます。
BACK INTO ENGLISH
She is jumping into the water.
That didn't even make that much sense in English.