In One Piece, there are giant gates protecting the entrance to Enies Lobby, Impel Down, and Marineford. They look about as long as an average giant (巨人) above sea level.
But, I was wondering how long are they below sea level. For instance, can Jinbe or any other fishmen swim under it?
I mean it can't stretch up to the sea floor and fishmen can swim up to 10000m deep. Or does it?
