He is in the northeast house in pacifidlog town (the floating town between routes 131 and 132).
wait for the old guy in the house in southeast Pacifidlog Town to say OMG i see Mirage Island Then you use SURF and go east from Pacifidlog till you reach Mirage Island
It is not available in Sapphire, but it is in Emerald. It's in the desert region on route 111. If you come up from Mauville City the Mirage Tower will be close to the entrance of the desert area. Sometimes you can see it, sometimes you can't so just keep going back and forth until you do.
Talk to the Fossil Maniac he lives to the left of fallarbor town then go to the desert to find Mirage Tower.
Go to pacifildog town and talk to the guy in the eastern house looking out the window. If he says " I can't see mirage island today keep coming back every day until he says he can see it then surf east.
You can see Mirage Island any time after you beat the elite four. It is a completely random event and only happens once in the game. The only way you know its there is if you talk to the guy in Pacifidlog who says: I can't see Mirage Island today. One day and one day only he will say that he can see Mirage Island. Hope this helps Skyra
You need to keep trying to put different Pokemon in your party, but Pokemon with different ID numbers. There is a random ID number for each game to let you see mirage island, and if the ID number is one of the Pokemon in your party, then the man will see mirage island, and you can swim towards it.
first you have to go in the desert then go right about 5 steps then go down until you see the mirage tower and come in the left way of the desert
he will see the mirage island only if you bring the Pokemon he's thinking of
its useless to get there..... still - enter the desert many times form Mauville.As you enter , walk a few steps forward. You will find a black person in blue dress (rock Pokemon trainor) .To his right side, you should see the mirage tower
you find mirage island outside pacifidlog town when you have a mirage sensitive pokemon. you have to talk to an old man in the southeast corner of town without a hat. if he says "i can see mirage island today!" then then you have a mirage sensitive pokemon and can visit mirage island on route 130 or 129
go to pacifalog and talk to the guy in the building all the way to the right. he will say he sees or doesnt see mirage island today.
He will see you later...... Simple