you get a ship defeat the evil capt. crawfish then you win
its in the middle of the map
On each island once you complete the missions for them.
i dont think that you can but you dont need it to get map
its the very top of the map of the islands for your boat on skull duggery island you have to signal the ship first then you can go there but look out for the pirates patrolling the water by Andrew bell
the skull on your map
go to your map and look at the bottom
You must defeat Captain Crawfish first. To defeat him, get all map pieces, get the warship "Phoneix Warbird", and hire all of the crew members if you could. Then you go to skull duggery island under Pirate Post, go near it then Captain Crawfish would appear to battle you. After you defeat him, sail back to Fort Ridely, then go all the way right to the Governor's house. Talk to the Governor to get the Bone Shovel and the Treasure Map. Sail back to Skull Duggery Island, then dock there. Swim all the way to the right until you reach an island with a black flag on the highest rock. Look at the treasure map, or just go to the rock that is beside the tree, and use the bone shovel. You would dig up the treasure... And you would have to find out the rest of it yourself :)
You have to go to each different island and that's where you'll find a piece of the map
grab it and you get an achievement
you have to find the map pieces on all the islands then you have to sail to skulldugry island
by the water
After you get all of the map pieces, go to your inventory and click to examine the map. The map would assemble automatically and a secret island would reveal it self on the map, named Skull Duggery. You could sail there to battle Captain Crawfish (one of the four villians!), but before that, you should get the battling ship "Phoneix Warbird", as well as hiring most of the crew members. (Because even with the Phoneix Warbird, it took me about 3 minutes, because it is really hard to aim while both ships are moving!)