According to Bulbapedia, Surf is obtained from Wally's parent's house in Petalburg. Before obtaining Surf, the player must have defeated the sixth gym master.
After defeating the sixth gym master at the Petalburg gym, the player must go to the house just left of the gym. Inside the house is Wally's father, who will give away the Hidden Machine (HM) 03 Surf.
Hidden Machines are items used to teach Pokemon specific moves. Hidden Machine 03 contains the move Surf in every generation of the Pokemon games. Surf is a damage-dealing, water-type attack and can be used outside of combat to traverse bodies of water.Learn More
In Pokemon Platinum version, HM03 Surf is located in Celestic Town and the player will receive it as a reward for beating the Galactic boss Cyrus. Route 210, which is the road to Celestic Town, is blocked by sick Psyducks, and to pass through the road, the player must first obtain the Secret Potion to use on the Psyducks.Full Answer >
HM03 Surf is located in Petalburg City and can be acquired from Wally's father after the player beats Norman, the Petalburg City gym leader. The gym leader also happens to be the father of the player's character.Full Answer >
Jirachi cannot be caught by normal methods in Pokemon Sapphire for Game Boy Advance. Special Nintendo events and GameShark cheat codes are the best ways to capture it.Full Answer >
Rock Climb is obtained via the item HM08 in Pokemon Platinum and other Generation IV Pokemon games. HM08 is found in Route 217 near a hiker's house.Full Answer >