17+ Granite Cave Map Omega Ruby UK. When you arrive in the granite cave, a hiker will give you hm05 (flash). And, unlike ruby/sapphire, there's nothing else for you here at the moment (at least not until you get the mach bike), so leave.
(the part you can reach right now, anyway.) speak to the guy on the first leave granite cave and return to briney.
This cave has three levels and gets darker as you go through it, requiring flash. Visiting the cave again is compulsory to defeat the game completely, as it is the only place when nosepass can be found. In granite cave, you can get it from steven. The two underground floors are shrouded in darkness, as such it is recommended to bring a flash pokémon.