To get to Mauville, you need to do a couple things.
1) Attempt to drop off the parts at the shipyard by talking to the man standing in front of the blueprints. He will say that you should go find Capt. Stern.
2) Now, go to the museum. Notice there are no longer any Aqua members blocking the entrance. Walk inside. But, before you go upstairs, talk to the Aqua Grunt closest to the door and he will give you TM49 (Theif). NOW head upstairs.
3) A couple of Aqua's will attempt to steal your package after talking to Stern, but once you beat them, he will take the parts, and the road to Mauville will be open. Just head North out of the city until you reach the Trick House. Once there, turn to your right. This is the road to Mauville.
mauvile city
Mauvile city at the bike shop.
Watson gives it to you when you turn of the mauvile city generator
You need to use the move Rock Smash which you get in Mauvile City.
In Mauvile city. You can get there by going to the boat after the second gym and giving the letter to Steven. Then the old man gives you the option to go to Saleport City. Go there and do some aqua stuff and go through a route then your there in Mauvile.
get a harbor mail. Then go to mauvile city,and then find a house left of the pokemart then she will trade you a coin case..by: kordell
The abandoned ship or Mauvile game center
If you go south of mauvile city you can use surf and then go right to reach a cave that's new mauvile.
Get the TM secret power from the guy standing next to a big tree above mauvile city. Them use on big trees, bushes and indents in the walls.
hes somewhere in mauvile city
You get the coin case in the house next to the game center in mauvile town.The lady will give you it.
Mauvile city. is it really that hard to find out?