You will need a boat to sail to the other 5 islands on Skullduggery Island. The raft will arrive after you read the parchment with the blue candle at the Governor's house. You will signal the raft from the telescope using a broken mirror.
The process:
Until you read the parchment, all you will see through the telescope is pirates.
To Leave Skullduggery IslandYou normally would return to Fort Ridley and jump up to the blimp at the sign. However, you can close your browser when you are docked at any island, provided that you "save" your game first. When you return, it will be to that dock.To Leave Fort RidleyThe beginning of the game establishes the setting of Fort Ridley and the other five islands. You will need a ship to leave Fort Ridley and begin sailing the seas.(see the related question)
Nothing until the very end of the game. Once you have all five pieces of the map, put them together to reveal the 6th island ("little Skullduggery"). You can go there but there is nothing to do. After you chase off Captain Crawfish in battle, the Governor at Fort Ridley will give you the location card for the Buried Treasure, and a bone shovel to dig with. Sail to Skullduggery and dig up the treasure.
Once you have the 5 pieces of the map, you still have to drive off Captain Crawfish, which requires a powerful ship and some skill at shooting the cannons. Once he is gone, go to see the Governor on Fort Ridley, and he will give you the treasure location and a bone shovel. Then you can travel to the hidden island (Skullduggery) and dig it up.
You will encounter Captain Crawfish if you sail in the waters around the new small island, Skullduggery. You will need a powerful ship (the Phoenix Warbird) to outlast him, and he runs off when defeated. Once you have the five pieces of the map, and chase off Captain Crawfish, sail back to Fort Ridley and the Governor will give you the bone shovel, and the location of the Buried Treasure on the hidden island. Go there and dig it up.
Once you have all five pieces of the Treasure Map, the 6th island, Skullduggery, appears on the map. When you acquire a powerful ship, and scare off Captain Crawfish, the Governor will give you the Treasure location and a bone shovel to dig it up. (see related question)
Instead of sinking, Captain Crawfish sails away. Return to Fort Ridley, where the Governor will give you the bone shovel and the location of the buried treasure on the new island, Skullduggery. Sail there and dig up the treasure.
The theme of Poptropica's 13th island, Skullduggery Island, is to help the port of Fort Ridley stave off the looting attacks by the dreaded Captain Crawfish. You obtain a ship and then trade among the islands to build your wealth, buying ever-larger ships and crews. Finally you can battle and defeat Captain Crawfish, and return the Buried Treasure to Fort Ridley.
Go back to the Poptropica blimp on Main Street where you entered the island.If you can't find it, you can use the Haunted House from the Store to exit to the Island Map.Special SituationsOn Time Tangled Island, return to the present using the Lab setting (12 o'clock).On Astro Knights Island, fly back to Arcturus (planet Poptropica, X-56 Y-52).On Skullduggery Island, sail back to Fort Ridley (center island).On Cryptids Island, return to Main Street via the Mews mansion using the helicopter.
first off: learn how to spell! the easiest island is astro knight and skullduggery the hardest island island is early poptropica
Although you can go there and look around, there is nothing to do until the end of the quest, once you have driven off Captain Crawfish and the Governor gives you the location of the Buried Treasure on Skullduggery.
The 6th outlying island is hidden until you collect all 5 map pieces (one from each of the trading islands). It only comes into play after you have driven off Captain Crawfish and have the Treasure Location card from the Governor. Travel to Skullduggery and use the bone shovel to dig at the marked location.
The Jolly Roger flag is on the top of the mast at the Pirate Outpost. The flag that marks the treasure is in the middle of the hidden island (Skullduggery). When you have chased off Captain Crawfish, you can get the bone shovel and treasure location from the Governor. Go to the island and dig it up.