Team Aquas underwater hideout is located in Mossdeep. You will need to dive down in the water and on the right hand side there will be a cave, which will be the hideout.
in the undercombs of the sea
you battle them
near team aquas hideout in sapphire. but in emerald it is on MT. chimeny
it is in pacifidlog town i think
there hideout is by lilycove city and it closes up in end of game:)
You have to beat team aquas leader. His red orb will glow and kyogre will wake up.
A rock in the front is a good hideout to pass em
you go to modseep and vs the gym
lilycove city or something like that
team aquas hideout in lilycove
look up walkthroughs on youtube
Near sootopolis underwater
Go to Slateport City, go to the boat port and after the cutscene, the hideout will be accessible.