YOU SAID:
He couldn't hit water if he fell out of a boat
INTO JAPANESE
彼はボートから落ちても水に打てない
BACK INTO ENGLISH
He can't hit the water even if he falls off the boat
INTO JAPANESE
彼はボートから落ちても水に落ちることはできない
BACK INTO ENGLISH
He can't fall into the water even if he falls off the boat
INTO JAPANESE
彼はボートから落ちても水には落ちない
BACK INTO ENGLISH
Even if he falls off the boat, he won't fall into the water.
INTO JAPANESE
たとえ船から落ちても、水には落ちません。
BACK INTO ENGLISH
Even if you fall off a ship, you won't fall into the water.
INTO JAPANESE
船から落ちても水には落ちません。
BACK INTO ENGLISH
Even if you fall off the boat, you will not fall into the water.
INTO JAPANESE
たとえ船から落ちても水に落ちることはありません。
BACK INTO ENGLISH
Even if you fall off the boat, you will not fall into the water.
That didn't even make that much sense in English.