Visit the Poketech Company in Jubilife City and speak to the President. He'll give you the LINK SEARCHER application for your Poketech.
Also some areas have been made accessible, now that you have the Surf ability.
Surf on the small pond in front of your house to find an ODD KEYSTONE. Locate the item using the Dowsing Machine.
Surf on the water located south of the area. Head west. Defeat the Trainer. There is a boulder here that needs to be pushed using Strength to get an EARTH PLATE. Surf on the water again and go norththis time. Smash the rock, then push the boulder left for a TM01 (Focus Punch).
Surf on the larger pond and go east to find an HP UP.
Head west from the entrance, smash the rocks and surf on the water. Follow the water to the end. Grab TM03 (Water Pulse). Go back into the water and head for the north bank. Break the rocks along theway for a LUCK INCENSE at the end.
Surf on the pond and head north for TM24 (Thunderbolt).
Access this area via the south exit in Veilstone City. Surf on the pond and check the northeast portion for a RARE CANDY.
Surf on the water to the right of the Poke Mart. Go east then north for a MYSTIC WATER.