mlarox

Note: to open the door, you need and wailord (evolves from wailmer @ lv.40), and a relicanth (bottom of the sea)

Ok this may take a few tries, but go to pacifilog town, and to the west there are strong currents. Keep going through the currents and you will find and space where you can dive. Dive down, and you will find a cave. Go in, and go to the back of the room. There should be a wall with brail writing on it. Now put relicanth on the the top of your list, and wailord at the bottom. Now "read" the brail. There should be rumbling and it will say something like, "it sounded like doors opened far away". note: there might be a first room b4 this one. If there is, walk to the center of the brail writing wall and use dig

Regirock=desert
Regice=ocean near dewford town
Registeel=near foretree city

In order to get to the room where regirock is, I believe you have go to the wall, walk 3 steps to the right, 2 steps down and use strengh. for regice, when you walk up and "read" the brail, all you have to do is wait about 2-3 minutes and it will open

For registeel, go to the center of the room and use fly

Hope this helps, and good luck:)