go to the team aqua's stole submarine and use dive.
use the hm dive
you use dive in emerald and get waillorrd in ruby and i DONT NOW HOW TO IN SAPHIRE
Kyogre.
wala
Go to Seafloor Cavern and look around.
u find it at the seafloor cavern
the undersea one on route 128 i think.
You can find them in the underwater cavern
The Seafloor Cavern is an area in Pokémon Emerald which is found on Route 128. The Cavern is not accessible unless the player possesses a Pokémon with the HM moves Surf and Dive.
They have two ways out. One way is in the middle where you enter a town, from there you can fly, and another way is towards the north of the middle.
erwater cavern surrounding sootopolis city
Seafloor Cavern. To get there you need surf and dive, and once in there you will need strength and rock smash. Seafloor Cavern can be found underwater in route 128.