How are the Regis obtained?
Start off by going to Pacifidlog. Make sure you have Relicanth, Wailord, a Pokemon with Dig, a Pokemon with Dive and a Pokemon with Surf with you (these do not have to be separate Pokemon; ie: you can have both Dive and Surf on Wailord and it will still work). Surf towards the west and get into the currents. It might take you a few tries but eventually, you’ll find a patch of water where you can Dive (I’m not giving away the exact locations; makes the game more fun). Dive in and you’ll soon reach a Braille inscription. Resurface directly in front of this inscription. Walk towards the north and until you get to the wall. You should see another Braille message. Use Dig right in front of this one. There will be an opening in the wall. Enter and walk towards the wall again. Put Relicanth in the first slot of your team and Wailord in your last slot. Read the inscription and you will soon feel the earthquake. The Regis have been unlocked. Regice: Surf north of Dewford, staying to the left. R