Ruby & Sapphire Mirage Island
Most days, Mirage Island simply isn't there. An old man in Pacifidlog checks for it each morning, and only a rare one-in-thousands match lets you land and meet the Wynaut living there.
Mirage Island is in Hoenn. In the story you arrive from Route 130 to the south and it comes before Route 131.
MIRAGE ISLAND MAP
Mirage Island Walkthrough
Every wild encounter in its grass is a Wynaut.
- 1From the east shore, go west along the beach below the cliffs, up the wooden stairs and north past the trees, then east through the tall grass to the berry tree.
Pokemon Encounters
Mirage Island surfaces for a single day out of tens of thousands, and its grass holds nothing but Wynaut. Catching one in the wild is more a feat of luck than a hunt, since the island almost never appears.
Wynaut
Also found in 1 other location
Mirage Island Guide
Each day the game rolls a hidden number, and the island east of Pacifidlog shows up only when it matches the low two bytes of a party Pokemon's personality value. The odds are tiny for one Pokemon and improve with a full team of six. Ask the old man in Pacifidlog's southeast house, who tells you when it's visible.
The island holds wild Wynaut and the game's only Liechi Berry tree. Honestly, most players visit just to say they got there. Keep a full party and check the Pacifidlog watcher daily, since the island almost never appears two days in a row.