Once you defeat Captain Crawfish, and collect all five map pieces, you can go to the new island (Skullduggery) and dig up the buried treasure. Before you have done these two tasks, the island has no purpose. After Captain Crawfish has been chased away, the Governor will give you the treasure location and bone shovel.
(In order to beat Captain Crawfish, you will need the strongest ship, the Phoenix Warbird.)
In the left hand lower corner is the secret island. but you must beat captain c. before you can access it.
Sail anywhere near the new island or the Pirate Outpost and he will eventually find you and attack.
The treasure is on a secret island which is revealed after you find all pieces of the map, called Skullduggery. But I don't know how to get it yet.
skullduggery island!
Defeat the captain and go to the secret island of the Captain
The bank on Skullduggery Island is the Golden Harbor Bank, located in the Arabic-themed port at the lower right on the island map.
I think you go on Skullduggery and there is a secret island that appears on the map after all five pieces are assembled.
The 5 pieces of the treasure map reveal another small island (Skullduggery) where a secret treasure is buried. Once you get rid of Captain Crawfish, it will be safe for the villagers to recover it, and the Governor will send you to dig it up.
There is a dock at the bottom side of the small island, Skullduggery. The island appears when you have collected all 5 of the pieces of the Treasure Map.
Fort Ridley is the first place you go on Skullduggery Island. Its impossible to miss it.
Bouffant Bay is located northeast of Fort Ridley on Skullduggery island Poptropica.com
parrot port.