Pokémon Ruby and Sapphire/Capturing the Regis

You can capture the three Legendary Pokémon , and  in one great adventure.

Sealed Chamber
Start Surfing west of Pacifidlog Town; you will notice some strong currents that carry you to Slateport City. Enter these currents from their southern border. You might have to travel two or three times before you notice and finally reach the only dive spot in this route. Dive into it and swim southward; you will notice an inscription in Braille. It says Use Dive here to enter the Sealed Chamber. So, resurface at that spot to enter the Main Chamber.

Main Chamber
Inside, is a cave that has all ABCDEF... written in Braille again. The northernmost inscription reads Dig here. Use the Pokémon that knows the move Dig and a door will open leading to the Inner Chamber.

Inner Chamber
Here is a long message written in this chamber:
 * First row left: THOSE WITH COURAGE, THOSE WITH HOPE.
 * First row right: OPEN A DOOR, AN ETERNAL POKÉMON WAITS.
 * Second row left: BUT, WE SEALED THE POKÉMON AWAY.
 * Second row right: WE FEARED IT.
 * Third row left: IN THIS CAVE WE HAVE LIVED.
 * Third row right: WE OWE ALL TO THE POKÉMON.
 * Final row: FIRST COMES RELICANTH, LAST COMES WAILORD.

Switch the places of your party Pokémon so that Relicanth is at first place and Wailord is at the sixth place. Then press the northernmost stone.The cave will shake and you will hear three doors open. Now, visit the Ancient Tomb, Desert Ruins and Island Cave to capture the Regi's.

Island Cave
The hardest Regi to catch, Regice appears at the Island Cave on Route 105. Once you enter the chamber, the first thing you'll probably see is Braille written on the walls. To see Regice's moves and stats, look in the Pokédex section. Use a luxury ball to catch Regice easily.

Desert Ruins
As you might have noticed, all the chambers have six rocks encircling them. This symbolizes the six "eyes" of each Regi. The Desert Ruins is located in the desert! Regirock is located here, all chambers are pretty much the same in description in this part of the guide, so for more info check the Route 111 section of the guide. And an interesting side note, above the Desert Ruins is a Ruin Maniac named Dusty (for more info on the trainer Dusty look in the Trainers section) who says he's looking for some ancient ruins.

Ancient Tomb
Sort of like the Desert Ruins, the Ancient Tomb has a hiker (but not a trainer) looking for ruins. Even after you open the door, he still is looking! Well, anyway Registeel is here. Go to the middle of the cave, and use Fly. and a door will appear that leads to Registeel.

Advantages of the Regis

 * Enhance your Pokedex.
 * They are the only legendaries in Ruby and Sapphire that can enter the Battle Tower.
 * They have pretty good stats and movesets which benefit them in Contests and Battle Tower.
 * You can brag to friends about having them.
 * Can be imported into Pokémon Diamond and Pearl to get the incredibly powerful Regigigas.