First you will need the HM Surf. Now, go back to Nuvema Town, and then head off onto Route 1. Go past the grass patch, but when you see the first person, you will also see some water on your left. Go over there and use Surf. You are not yet on Route 18, but are close. Once you are on the water go down, then left and hop off onto land. Now go down to the end of the dark grass. Go left now, because there is gate! Once in the gate go through and you are now on Route 17. Once again, hop in the water. But now go on the walkable part. Walk across, hop in the water again, and get on the currents (Warning: Only one of the currents lead you the right way. This current is the bottom one). So now you see more land, then jump on it, check your Map and according to it you are now on Route 18!
you have to have the move surf, when you go back to route one you will see a guy in a green shirt there is water near him use surf there and you will find it
Route 18. Far West of the route.
You get HM Waterfall at the end of Route 18 on the strip of grass in Pokemon Black.
Route 18
Larvesta hatches from the egg. Hope this helps :)
Route 18. Walk around in the dark grass.
There in route 18
Surf west of route 17.
Route 18.
Route 18.
Route 18
Route 18. Far West of the route.
you get it in route 18
HM05 Waterfall is on Route 18.
You can find it on route 18.
route 18
HM Waterfall can be found on Route 18 in Pokemon Black and White.
Go to Route 1 and surf over to Route 18.