This is because you have to go in the cave at the top of the town then the gym will open.
Sootopolis city.
Underwater around sootopolis city and mossdeep city
In the sootopolis city gym.
erwater cavern surrounding sootopolis city
you get it at cave of origin but you have to beat the gym leader of sootopolis city to use it on the waterfall to ever grande city
in sootopolis city
sootopolis city
sootopolis city
underwater near sootopolis city
Sootopolis city.
Underwater around sootopolis city and mossdeep city
Underwater, in the grass outside Sootopolis City.
sootopolis city
Sootopolis city but you cannot go in.
you dive at route 128 by sootopolis city
In the sootopolis city gym.
It's in the Cave of Origin in Sootopolis city.