How do you get to moss deep city in emerald

It's quite easy. First, you need to beat the flimsy team aqua. Note that in the hideout is the master ball but dont ask me how to get there I don't know. So after you beat team aqua they will leave lilycove and the wailmers are out of the cove. You can then surf over route 124 to Mossdeep! Have fun!