Pokémon Ruby and Sapphire/Capturing the Regis

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

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. 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.

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 POKEMON WAITS.
 * Second row left: BUT, WE SEALED THE POKEMON AWAY.
 * Second row right: WE FEARED IT.
 * Third row left: IN THIS CAVE WE HAVE LIVED.
 * Third row right: WE OWE ALL TO THE POKEMON.
 * 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.