Go to Rayquaza in Sky Pillar on route 131
When you get Rayquaza to stop Kyogre and Grouden from fighting Wallace will give you waterfall but then you have to get sootopolis gym badge to do it.
first you have to beat team magma completely and then you must stop groudon and kyogre from fighting you can do that by calling rayquaza
go in the cave in the same town and there is a person there and talk to him and thay will stop fighting
you have to catch or kill kyogre
You go to Sootopolis City. There you will see Groudon and Kyogre fighting, and Rayquaza goes to stop them. Then he goes back to the Sky Pillar.
you have to catch or kill kyogre
by rayquazar (from Electchu: OR get them to shake hands -lol- )
Go to Sootopolis City to watch Groudon and Kyogre still fighting then Rayquaza will appear in a cutscene and stop them from fighting. Once you beat the Pokemon league go back to Sky Pillar to capture Rayquaza.
you don't need a key, you need to stop kyogre and groudon from fighting , if they aren't fighting, find the submarine.
You go find rayquaza at the sky tower. (Behind the town on the water)
because you need to get kyogre and groudon to stop fighting and to do that you have to go to pacifidlog and surf east until you can find your way in a cave to the north heres a link to the map http://img122.imageshack.us/i/hoennkd5.jpg/
First talk to Archie and Maxie after you get rayquaza to make groudon and kyogre to stop fighting, then talk to steven then Wallace and Wallace will give you waterfall. Hope that helped.:) After getting rayquaza ( Sky Pillar east of Pacifidlog Town ) to stop Groudon and Kyogre, talk to Wallace in front of the sootopolis gym