Where do you find the town map for Pokemon emerald version?

Ok,

Unlike most Pokemon games where you get the town map before you leave your home town, you get this one a few towns on. You get it from the town of rustboro. After you do there what you have to do, you go to a cave where a man states he had his peeku stolen. Go in that cave, and you see a team aqua member with his bird, kill her and he will come in and thank you, take his bird and tell you to come see him sometime. Then as you walk out a man will greet you and take you back to Devon corp where they will give you a poke nav, in here is the map. After you finish, head back to mr brineys cottage and set sail for dewford.