you get HM waterfall on route 18
there is no hm waterfall that i know of
If you're talking about getting to the third boulder to push it into the pit, you don't need the hm waterfall. I thought so too, but then just try swimming up the upside down waterfall. It worked for me.
there is a hm called waterfall
HM 7 (waterfall) is in island 4
You get the HM waterfall in the same cave you get Kyogre
U find the HM Waterfall in the cave of origin.
HM, Waterfall is in the Ice Cave on Four Island.
HM Waterfall is given to you by Gym Leader Juan after you beat him.
you can only get the hm waterfall if you beat the sootopolis gym leader juan
you have to get the HM waterfall to go over the waterfall