Pokémon Ruby and Sapphire/Walkthrough/Dewford Island

Go into the house to the south of Petalburg Woods. Talk to the person there, and tell him to bring you to Dewford. Head north along the shore, and face:

Fisherman Ned (480)
Pokémon	Type	Level	Move 1	Move 2	Move 3	Move 4
Tentacool	Water/Poison	12	Constrict	Poison Sting	Supersonic

And after him, face:

Fisherman Elliot (440)
Pokémon	Type	Level	Move 1	Move 2	Move 3	Move 4
Magikarp	Water	11	Splash
Tentacool	Water/Poison	8	Poison Sting	Supersonic
Magikarp	Water	11	Splash

You are now next to Granite Cave. Go into the cave. In this cave, you can catch Geodude, Zubat, Makuhita, Aron and {{{2}.

Talk to the person there. He will give you HM5 (Flash). Continue along the route. Pick up the Escape Rope, then go down the ladder. Take one step to the west, and then go north. Head to the east (you will have to move slightly to the north, and later to the south). Go down the ladder. Head to the north. Go along the north wall. Head up the stairs. Go to the east and then up the ladder. Head to the west and up the next ladder. Head to the west end of the cave, and you will see what looks like a way out. Go through. Talk to the person in there. He will give you TM47(Steel Wing). Head out of that room. To leave the cave, jump down the ledges.

In the house to the north of the ship dock, talk to the person on the right; he will give you a Silk Scarf. The person to the east of the gym will give you an Old Rod.