there is only two and you can find them in undella bay that's the only place you can use dive which i in the dark spots
Undella Bay
In the darker patches of waters while Surfing.
Undella Town, and you use dive in four dark water spots to get to the abyssal ruins.
You can get water stones by getting a blue shards.to get the blue shards, you have to get the HM Dive. have to beat the gym leaders in moss-deep to use Dive .You only can use Dive at places on the ocean that look like they have a deep areas.Dark-blue
any water Pokemon can use dive
You need to get the HM dive from Steven in Mossdeep City. Then you will have to beat the gym leader in Mossdeep City. Then you will be able to use the HM dive. And you find the dark spots in water while surfing. Use dive. And to resurface. Use dive again!
Undella Bay in those dark spots in the water (not ripples) transports you to Abssyal Ruins or whatevar
you just need to have the HM dive give it to a water type pokemon that can use it go to undella bay and use over a black spot and you see what it looks like under the water BTW-you dont do much ,it just shows you what it looks like.
you need to use a water type pokemon and teach it dive or use action replay
first of all how do you get dive in the first place?
simpliy the dark spot leading to sootopolis you have to use dive
When you Surf, you will see dark spots in the sea. You can then use Dive, and go underwater.