you need to use surf near the city with the beach
Surf from Olivine
cianwood
Cianwood City
you have to surf to cianwood
The Pharmacy is in Cianwood City.
In Pokémon SoulSilver, you will get the Fly HM in Cianwood City but only after defeating Chuck, the Cianwood Gym Leader.
You can find mantyke on cost of cianwood city
surf from olivine to cianwood
You get it from defeating Chuck in Cianwood City from a lady.
in the caves
Surf to Cianwood and visit the pharmacy there.
You need to go to Cianwood Pharmacy and get the Secretpotion.