When I left the Rustboro Gym, I found out that a Team Aqua member had stolen some Devon employee's GOODS
whatever those are. I had to go out to the Rusturf Tunnel in order to confront the grunt. After I defeated him in battle, I recovered the goods and also rescued Mr. Briney's Wingull, Peeko, from certain doom. When I ran into the Devon guy again, he took me to the top floor of the Devon Co. where the president gave me the Pokenav as well as a letter to give to Steven. I then left and headed back down to Route 104. There, I went to Mr. Briney's house and he took me to Dewford Town on his boat.