When you make the boat and go to the island where the mango and the naked-teacher-music ladies is, you will find a metal pole near the crashed airplane that can be used to make a crowbar. DO NOT MAKE A CROWBAR! it will get you into the ship, yes, but there is nothing of much value in there so it's a HUGH waste of material. The metal pole will need to be used later on to make a fire pit for the chef which is way more important than getting into the ship.
In the ship there is a box you can get stuff out of but its only decorative stuff, nothing that will advance your game.
Please hed this warning, unless you have two metal poles or someone can GUARANTEE you the location of another one, you DO NOT MAKE A CROWBAR before you make the chefs fire pit!