Ace, tried to challenge Whitebeard and finally failed, he didn't want to kill him so he carried him unconscious to his boat full of crew. Ace hated being there and always wanted to kill Whitebeard but always failed. Ace didn't like anyone there, even though they treated him so well, Ace tried to change him but he always refused. Whitebeard had a biological daughter on that ship, everyone treats her like their little sister