have your back up Pokemon be like sabley or you can just train your Pokemon A LOT
mosdeep gym or from gardevoir
After beating Mosdeep City Gym.
Tate & Liza in Mosdeep. Psychic type.
beat the mosdeep city gym and talk to steven inside his house at the top left house on mosdeep
After you defeat the mosdeep city gym and the team aqua (also in mosdeep city but only after you finished the gym) you can get dive from the guy in the house in the south-west of mosdeep
beat the 8th gym
after you beat your father's gym
Defeat all of the Gym leaders on Emerald. ~KKMG1
Go in. Beat the GYM. THAT SIMPLE
Mosdeep City Surf there from Lilycove
...you beat the gym leaders
go to slaport :)