After you defeat the Mossdeep City gym leaders, you can either go to Sootopolis City or you can go to the Seafloor Cavern to defeat Team Magma. I would suggest going to Sootopolis City before you take on Team Magma so that once you've gotten through their hideout, you can just fly back to Sootopolis to capture the legendary pokemon.
Mosdeep in emerald, Sapphire and ruby
Go to the top-left corner of Mosdeep city and go inside the house. There's Steven, who will notice you and give it to you
in Pokemon emerald, Sapphire, and ruby, you can catch a seedot right after you leave oldale town. then give it an exp. share. go beat the elite four a couple of times then it will evolve into a nuzleaf. Then go to mosdeep city and dive for a while and you will find a green shard take it to the island with the house on it and get a leaf stone. give it to your nuzleaf and PRESTO! You now have a shiftry. Shiftry will helf you beat the elite four champion in emerald. But not in Sapphire and ruby. HOPE THIS HELPS! You can catch in ruby and emerald as a nuzleaf.
Evergrande city in pokemon emerald is east of mosdeep city. To go there you must surf and defeat any trainer. After you get there you use waterfall and go to victory road you must bring pokemon with flash,rock smash,strenght. You should defeat wally to.
go to ever grande city and defeat Pokemon league. affter that go find these legendarys listed.rayquazalatiosregi'iceregirockregisteel.after you are through with that then go catch every Pokemon possible in Pokemon sapphire.after that trade with Pokemon ruby to get the Pokemon only in ruby. Then buy a gameshark for GBA. you need it to get Pokemon from difrent regions such as lugia ho oh celebi -etc. when you have every Pokemon from these regions,hoen,jhoto and kanto then go to lilycove citys game editor. he will give you the diploma. you have then beaten the game.
go to mosdeep city and it will be to the north of it
go under water in mosdeep city( i think its mosdeep) and keep looking.
Mosdeep in emerald, Sapphire and ruby
Don't you mean "How to get to Sootoplis City in Pokemon Ruby?" Oh it's simple, get dive and dive underwater near Mosdeep City and find the path, then keep going down until you find a cave, go in the underwater cave and then dive again and there you are!
Go to mosdeep city,the space center. Defeat team mama leader. Then go to Steven house. He will give u. His house is at mosdeep city. Somewhere top left of city.
go to shoal cave above mosdeep city
Go to Mosdeep city and walk to the left side of the gym. The house at the very far left of the gym is Stevens house. talk to him and he will give the HM Dive
go to mosdeep city talk to the professor and he will take you to moon
go to Stevens house at mosdeep city i think it was?
The walmers blocking the sea will be gone. Then u can go to mosdeep city n carry on the adventures.
Go to Steven's House in Mosdeep City after you beat everyone in the Museum there.
you get it after beating tate and liza mosdeep city gym leaders and after defeating team magma in space center. Go to steven house in mosdeep city he will give you dive.