User blog comment:Kaido King of the Beasts/Chapter 821: Last March of the Elephant/@comment-5303512-20160331140559/@comment-5303512-20160331143946

Unless Jack can somehow find himself out of the sea, since he is a devil fruit user, who can't swim and most likely drowned by now. However with God Serena, he tried to fight the King of Dragons and got a large portion of his Stomach ripped out and is pretty much dead, that is very legitimate.