Well you dive up when you've reached the end of the dive spot with 6 rocks. Then use dig at the top wall in the sealed chamber. Then go into the next room and have ralicanth first and wailord last in your party and inspect the top wall there and a earthquake will happen. Eureka! You've now opened the regi doors but theres more braille decoding to be done....
Braille
Get the leg pokemon mewtwo
The Braille reads: "DIVE"
Braille key. With each Pokemon Ruby, Sapphire, Emerald, FireRed and LeafGreen version, you should obtain a Braille Key in the box. This gives you the symbols and the letters they stand for - which are used in the game. If you do not have this, it is easy to find. Wikipedia gives a Braille key under the heading "Writting Braille". Pokemon only uses the alphabetic letters and the symbols for the full stop and the comma. http://en.wikipedia.org/wiki/Braille
If you mean the Unown symbols, they are Pokemon! They are also considered a type of writing. Each Unown is a letter, from A-Z. They can also be ! or ? marks. For more info on Unowns, and what they can look like, you can try out Bulbapedia. Here's the link: http://bulbapedia.bulbagarden.net/wiki/Unown
you have to get a Pokemon that knows dig with you and then use dig in front of the first braille
There will be a translation in the instruction manual that comes with the game. If you don't have this manual, look up "How to decode braille" There probably won't be any results if you add the "in Pokemon Emerald part
On that Island, where you found those dots, called Braille, have a Pokemon that knows the HM Cut. Use Cut on and facing the door that contains the Braille message as if it were a tree! And within, I forgot what the cave contains. Sorry! You can learn how to decode those dots, Braille, with the Internet. Just type in Braille on Yahoo! or Google Search to find the letters of the American alphabet translated to Braille!
When you buy the game you normally get a page with braille on it but if you missed out or lost it you can just get a copy off the internet. You only need the alphebet and some gramma
Go check Gamefaqs.
Louis Braille developed his tactile writing system over several years, starting at the age of 15 after he lost his sight. He created the first version of his alphabet in 1824, and by 1829, he had refined it into a more complete system. In total, it took him about five years to develop the Braille system that we recognize today.
You can complete the pokedex on Pokemon Blue version by trading with you friend who has Pokemon Red version. Or you could do what I do and get two gameboy color's and multiple Pokemon games because none of my friends play Pokemon anyomore; even though it is one of the best games of all time =).