When I arrive at Lilycove City, the Wailmer/Wailord blocking the way to Mossdeep City are always there. I can't work out what I keep missing in the storyline to get rid of them. Unless it is possible to bypass them by riding Latios/Latias, I haven't got a clue as to what I keep missing in order to get there.
To be honest, I could never work out how to get past them in the original Ruby/Sapphire either!