I think I'm almost at the end but now I'm stuck.
Spoiler
I have fed all creatures except the "Panhandler". I just have my suit and nails left in the inventory. I can't find the board the guy in the bar with the bird skeleton is talking about.
Spoiler
Jack would likely hide it under some mark on the floor on the main deck of the ship so he could find it. If you walk over a potential mark, you'll probably hear the squeak.
Thanks, I was able to finish the game :)