First you have to deafeat Team Magma In Mount Chimney. Then go to slateport city to the dock building where you run into team aqua stealing a submarine, then you go to Lilycove and enter Shoal Cave. The two Team Aqua Grunts won't be there any more so you can pass through. Fight all of Team Aqua and The person Team Aqua Grunt that was training will not be there any more so you can surf past them. Keep Surfing until you get to Mossdeep and Mossdeep is a Diffrent Story.
mossdeep city
Sootopolis city.
Underwater around sootopolis city and mossdeep city
I think he is near or in Mossdeep City.
The super rod is received in mossdeep city.
mossdeep city dhoom
In Mossdeep City.
Mossdeep City.
mossdeep city
look in mossdeep city
Sootopolis city.
In Pokemon Ruby/Sapphire/Emerald in Mossdeep City.
Underwater around sootopolis city and mossdeep city
The Space Center is located on a hill on Mossdeep City's eastern side.it is in mossdeep city
You can get Dive in Pokemon Emerald by going to Mossdeep City and ensure you check all the houses.
I think he is near or in Mossdeep City.
In Mossdeep City from Steven after you have defeated Team Magma.