Located on Route 108, the Abandoned Ship is all that remains from when the S.S. Cactus ran aground. The old vessel has many rusted holes, broken doors, and furniture scattered around. Navigating the structure requires the use of both Surf and Dive. Once slated for demolition, the half-sunken vessel now exists as a refuge for water-dwelling Pokémon.
Three of the four cabins here are connected. Visit the isolated northwest cabin for a Harbor Mail and head downstairs.
Fight Sailor Duncan and collect a Dive Ball from the north-central cabin. Visit the southwest cabin for an Escape Rope and climb the stairs in the northwest corner.
Pass through the north cabin to get a Revive, then go through the south door to reach the outside of the ship. Climb the stairway there to reach the Captain's office.
The Scientist inside is investigating the ship on Captain Stern's behalf. Stern asked him to find a Scanner, but he hasn't had much success. Pick up the nearby Storage Key and return to the basement floor.
Inspect the locked door to the northeast cabin to insert the Storage Key. The key becomes stuck in the lock, but the door opens. Inside, you find TM13 (Ice Beam). After that, head for the south-central cabin. Seawater has flooded into the room, so use Dive to traverse an underwater hallway that leads to an isolated part of the ship.
This part of the ship has six cabins. Rooms 1-3 are located on the south side, and Rooms 4-6 are found to the north. Four of these rooms are locked, and although Room 5 is unlocked, there is debris blocking the door.
Enter Room 3 to see a sparkle on the floor; this signifies a hidden item. Pick up the Rm. 1 Key from the northeast corner, and the Water Stone to the left before leaving.
There are two hidden items in Room 1. The Rm. 4 Key is located near the west wall, while the other item is just trash. The visible item is TM18 (Rain Dance).
In Room 4, inspect the trash can in the northeast corner to find the Rm. 6 Key.
Enter Room 6 and collect the Luxury Ball, then use the narrow hallway to reach the adjoining room. Room 5 has three pieces of trash and one item; the Rm. 2 Key is located three steps south of the left-hand trash can.
When you return to Mauville, you find Wattson standing near the Pokémon Center. He asks for a favor, and explains that the city has an underground sector known as New Mauville. There's a generator inside that hasn't been functioning properly, and he needs you to go and turn it off before the situation gets out of control. He gives you the Basement Key and directs you to the facility's entrance on Route 110. Surf eastward under the north end of Seaside Cycling Road to reach the facility.
New Mauville, Entrance
New Mauville, B1F
New Mauville was intended to be an underground city extending dozens of floors below the surface. However, the project died in development when it was discovered to be a habitat for wild Pokémon.
Use the Basement Key to unlock the door, and step inside to reach the southeast room.
The lower floor uses a series of colored buttons as a security measure; when stepped on, all similarly-colored doors open while all others close. Step on the blue button in the entrance room and go west. Press the green button in the next room and continue on. Pass by the third button and head north to reach an Escape Rope; collect the item and press the blue button beneath it. Go northwest to find a room with two items, a Parlyz Heal to the left and a Voltorb to the right. Follow the hallway eastward to the north-central room and another pair of items, a Voltorb to the left and a Full Heal to the right; collect the item and step on the green button beneath it. The generator is located in the northeast room; press the red button to shut it down and collect the Thunderstone before leaving the area.
With your task complete, return to Wattson outside the Pokémon Center. Inform him that everything is all right in New Mauville, and the grateful Gym Leader rewards you with TM24 (Thunderbolt).
Route 129 lies to the south of Route 128. Though an optional route, the several Trainers found here make it a worthwhile place to explore.
While Route 130 usually appears as a simple stretch of ocean, it is sometimes home to a strange island that seems to appear and disappear. The island is inhabited only by Wynaut, which range in level from 5 to 50. A soft soil patch on the island's east side holds a single Liechi Berry tree. This is the best Berry to use in Pokéblocks, as it will produce Gold Pokéblocks.
Route 131 lies between Route 130 to the east and Pacifidlog Town to the west. There are no underwater trenches in this stretch of ocean, but several Trainers on the surface are looking to battle. On the route's north side is a large island, currently off-limits, that is home to the towering Sky Pillar.
Visit the northeast house and talk to the girl inside. She tells you a mysterious bit of wisdom passed down from her grandfather: Six dots open three doors. Her father also remembers hearing tales of three Pokémon representing the powers of Rock, Ice, and Steel. It seems that Hoenn still has some secrets to discover!
The old man in the southeast house spends his time by scanning the horizon for Mirage Island. Speak with him every day to learn if the island has appeared.
Time for a Trade
The woman in the south-central house is having trouble catching different Pokémon around town. She wishes to trade her Corsola for a Bellossom. Corsola can be found on Route 128, but almost never appear. Bellossom evolves from Gloom, which can be found easily in several areas, including the Safari Zone.
Friendship is Everything
Stop by the southwest house to meet the brother of the Pokémon Fan Club chairman. Have him evaluate your relationship with your lead Pokémon, and he'll reward your friendship with TM27 (Return). If your Pokémon is unfriendly toward you, he'll give you TM21 (Frustration) instead.