Here is where to get the Hms:
To get Cut, there is a house in Rustboro City where this one guy gives it to you.
To get Flash, go inside the cave near Dewford Town and a hiker will give it to you.
To get Rock Smash, there is a house in Mauville City where a scientist gives it to you.
To get Strength, go to that cave where you can only find whismur and use Rock Smash to help the man get to his girlfriend. In exchange, the man will give you Strength.
To get Surf, beat the 5th gym leader in Petalburg and go next door to Wally's House and his dad will give it to you.
To get Fly, get past the Weather Institute and battle May. If you win, she gives you Fly.
To get Dive, go to Mossdeep City. In one of the houses, a person gives it to you.
And finally, to get Waterfall, go to the Cave of Origin where you battle Groudon and right before you do, you will find Waterfall.