To Get To Rustboro City From Verdenturf Town, You Have To Have Rock Smash And Go To Verdenturf And Go In The Tunnel Then Use Rock Smash On One Of The Rocks, And You Can Get To Rustboro From There. Or You Can Use Rock Smash When You Go To Rustboro Then You Go In There And Go To Verdenturf. But You Do Have To Use Rock Smash Every Time. Hope It Helps.