U have to obtian dive and the go south and u will see a long strip and then u will go to a cave entrance and you will see a submarine use dive agn and there u go
First use the move strenght there are some doors that bring you out climb the steps an door behind you go in and go through th second cave hole
You will need to defeat the Team Aqua or Magma grunts in the Seafloor Cavern and make your way though their ranks to the leader of Team Aqua/Magma.
well you go swim then find the dark spot of the largest sea then face the same pokemon then catch it,the battle team aquas
Mt. Pyre
I think it's in the seafloor cavern.
They are in Seafloor Cavern. Things you need to get there: Surf HM Dive HM First Surf directly downwards Mossdeep and then Dive at the first dark Patch you see.Follow the route until you see a hole.go through it and you will find a submarine.Surface and you are at Seafloor Cavern!
then they will be at there hideout in lilycove city or if not there then at the slateport harbor
You have to beat team aquas leader. His red orb will glow and kyogre will wake up.
you go to the team aquas submarine then use dive then your in sea floor cavern and make sure you battle everyone
Their base is always at Lilycove, but you can find them other places (Mt. Pyre, Underwater Cavern, etc...).
earthquake in Sapphire will be found in seafloor cavern in the room that you battle Archie of team aqua
South of mossdeep city you will sound find a diving spot that leads you to seafloor cavern this is where team aqua is.
they leave kanto to find more rarepokemon with the rocket leader (8 gym leader).