Sunken Ghost Ship

The Sunken Ghost Ship, also known as the Mysterious Sunken Ship, is a location in Super Mario World that serves as a gate to the Valley of Bowser. After defeating Wendy O. Koopa, Mario (or Luigi) has to swim through this haunted ship in order to make the doorway to the Valley of Bowser come out of the sea.

While Shogakukan coverage considers the Sunken Ghost Ship to be part of Chocolate Island, Super Mario Advance 2: Super Mario World considers it part of the Valley of Bowser, as do the Nintendo Super System arcade remake of the original and Mario Mania. On board the ship are some Bullet Bills, Floating Mines, Koopa Troopas, and a massive Disappearing Boo Buddy swarm, marking the only appearance of Boos outside Ghost Houses in the game and, thus, the only time Yoshi can be seen with ghosts in the game. This is also the only level in Super Mario World that has a Magic Ball.

The Super Mario World manual mentions that the Sunken Ghost Ship was once one of the Airships used by Bowser along with the Koopalings in Super Mario Bros. 3; the Magic Ball found alludes to it being found in Super Mario Bros. 3 Fortresses. However, its front does not match that of any Koopaling's Airship.

The level Haunted Shipwreck from New Super Mario Bros. U bears a lot of similarities to this level.

Overview
The player comes out of a Warp Pipe underwater next to the sunken ship. There is a ? Block and Bill Blasters nearby. The player must then go down another Warp Pipe that leads under the deck, where Eeries and a massive Disappearing Boo Buddy swarm can be found, appearing and disappearing in locations at a constant pattern. After passing these, there are Circling Boo Buddies and two more Boo Buddies. Then there is another Warp Pipe that leads to a huge drop. When the player starts falling, there is a Super Star that can be grabbed. On the way down there are Dragon Coins, falling Koopa Troopas and Koopa Paratroopas. There is a platform halfway down with a ? Block that contains another Super Star. Farther down, there are huge bunches of coins and falling Floating Mines. The player must fall to the right to avoid falling into the water with the Floating Mines, though if they do, they can collect a few 1-Up Mushrooms near the bottom before they risk falling off the screen. There is a platform on the right with the green Magic Ball that must be touched to beat the level. These 1-Up Mushrooms do not appear in the Japanese version.

After Mario beats the level, a giant cave entrance that looks like Bowser's head will rise up out of the water. Mario will enter the cave, which leads to the Valley of Bowser.

Although the Dragon Coins in this level are rather difficult to obtain due to the speed of falling, Mario as Caped Mario can easily drift down the level and get the Dragon Coins; being Caped Mario on Yoshi can allow the player to Spin Jump off Yoshi into missed Dragon Coins.