When you enter Mauville from the south, on the far right there will be a house. Go into the house and speak to the guy there, he'll give you the TM for it.
You can get rocksmash at the Pokemon center at the city were the gym leader uses electric type of pokemons.Just talk with the scientist.
rocksmash isn't a HM, it's a TM. but i think you get it from a gym leader.
there is a guy by violet city who gives you HM rock smash
This HM is received from an old man in the Ember Spa on One Island.
cut,fly,surf,streangh,flash,rocksmash and water fall
go to route 36 and talk to the guy in front of sudowudo
you can find it east of jubilife city in the cave a hiker will give it to you
In Sapphire/Ruby/Emerald, you must have the HM RockSmash, which a guy in a house gives to you in Mauville City. After that, get the Mauville Gym badge and then use RockSmash on the two rocks blocking you north of Mauville.
Go to one island. Then talk to every person. One of them has rock smash!
It is on shinou city,it is at front gate pokemon leage the nugget. HOPE IT HELP GOOD LUCK
In Third Generation Whirlpool is no longer an HM.
there is no such thing as rock break or if you mean rock smash it is not a hm. if you want to get rid of the huge rocks you need strength