l say this- ok well, you either have a Treeko, Torchic, or Mudkip as a starter. Mudkip is at a type disadvantage against electric, which is the Mauville Gym's Type. But before we jump that hurdle, no matter what Pokemon you started with, it MUST be evolved to take on Mauville. Either Grovyle, Combusken, or Marshtomp. I have found Rock to be helpful against electric, so make sure to have a Pokemon with some rock moves in your party. For example, at Roxanne's Gym, you get a TM, Rock Tomb, once you defeat her. I taught that move to my Mawile. You can find Mawile in Granite Cave in Dewford. So if you have a Marshtomp, don't despair! Try to catch a Mawile and Geodude in Granite Cave, and level them up on route 110, which I find a great training ground for Pokemon level 10 and up. Also it mainly consists of electric Pokemon.
You can still use mudkip he is ground/water. His mud moves will do tons of damage to the enemy, and I used him it worked fine I didn't have any problems.
Giovani left his gym to join Team Rocket as their leader. you must beat cinnabar gym then he will be there.
You head north from maville. Make sure you have Rock Smash.
it is the grass type gym leader, gardenia. She is the second gym leader. Oh and you also get your bicycle there AFTER you beat the gym leader, and the team galactic comander, Jupiter. . . your welcome ^ ^ O
go to dragon den and get elders approval catch lugia and face the Pokemon league
You have to beat the gym leader first... then you'll find them there.
First beat the Mauville Gym leader, Wattson.
Mauville City But you have to beat the city's gym leader before you can turn off the generator in New Mauville City
You get it from the gym leader. After you beat Norman(Petalburg Gym leader) and get surf, go to Mauville and the gym leader will be standing in the middle. He will give you the key. Then go down near the cycling road and surf. Then go right and you will see a cave.
The sixth gem is with Leader Winona in Fortree city. You need surf to get to that city. You get surf from Wally's dad after you beat the fifth gym. You surf there from Mauville.
Get Rock Smash in Mauville and head north!
in mauville city
You have to talk to the 3rd gym leader after you beat your dad and he is in the middle on mavlle city.And he will give you the key!
mauville city gym leader wattson
You get the third badge in sapphire when you get to Mauville. You have to battle Gym Leader Wattson in the Mauville City Gym.
The third gym leader in Pokemon Sapphire is Wattson and he is located in Mauville City.
challenge the saffron gym (psychic type gym leader)
In Ruby, Sapphire and Emerald, the 3rd Gym Leader is in Mauville City and in Diamond, Pearl and Platinum, the 3rd Gym Leader is in Veilstone City.