How do you get in the giant rock on route 120 of Pokemon emerald?

Im a little fuzzy cuz ive had my regis 4 a long time, but 1st you have to figure out the code in the cave to the left of pacifidlog town. (if u need to know ive already tanslated the braille) there are currents so you have to try them wisely till u land on an unmoving dark patch of water, then dive and figure out the braille...also need a Pokemon that knos dig and u need a relicanth to be at the front of your party, and a wailord at the bottom of your party. Use dig on the back of the room and walk into the back chambr. Then leave and go 2 route 20. Then u shood b able 2 go into the rock. That area iz full of keckleons, so u might have to use a Devon scope to get rid of it. U still need dig...oh and bring plenty of ulta balls, the regis, esp regice, can be hard to catch. They're all lv40.