Follow the path to the right of the vampire chick. On the beach there are 2 docks. the one
one the right will take you to it. And the Navigator is in the castle prison. you will
find him on your way to return the bloodvine ( if you retrace your steps)

you cant get him until you beat the vampire. once you beat him return to the prison with
the key and free him. then keep him alive until you get to the ship in the docks

When you see that Vampire girl thingy, you can walk through her blocks by running into her
when she is pushing you backwards. If you do it right, you'll be behind her and you'll
won't have to fight the other boss up ahead as a side effect! Good Luck!

Once you free Babik Nurn, the Navigator, you have to fight some more demon thingys.
Protect Babik Nurn from the demons until you leave.

There will be an exit if you go to your right after you talk to the vampire chick. follow
that until you find an exit, take that exit out. you will fight more demons there. if you
go on the correct dock, take a left and follow that to the shore and there you will find
the bloodvine.