How do you get the seventh badge on Pokemon Emerald?

Answer 1

seventh badgeto get to the city where the gym is, you have to have beaten the magmas at their hideouts and the aquas at Lilycove. then the wailmer they're training will get out of the cove. Take off Surfing where the Wailmer used to be and look at your map constantly to make sure you're on the path to Mossdeep. The gym will be there, but I warn you that they are the toughest gym, and your Pokemon have to be like lv.50 to beat them. They might not look tough at first, but they ARE. Hope I helped.:)
you have to find out what team magma and team aqua is doing then go ahead