Things You'll Need
Instructions
Go to the southeast hut on Pacifidlog Island.
Save the game at about 11:55 p.m., according to the in-game clock.
Talk to the man in the hut right after the game time goes to midnight. He will tell you if he can see Mirage Island.
Reset the game and open your saved game if he cannot see the island. Keep reloading until he can.
Exit the hut once he says he can see Mirage Island.
Use the Pokemon with SURF to swim on the water.
Head east through Route 131 to get to Route 130.
Head east through Route 130. You will run into Mirage Island.