Instructions
Go to Lilycove City, east of Route 121. Leave the city through the western exit and keep walking until you see the docks.
Get in the water and surf to the east. When you can go no further, surf south. Get out of the water when you reach land.
Enter Mt. Pyre. You are in the lobby. Head up the stairs to climb to the top of Mt. Pyre.
Jump through the hole in the floor to reach another part of the main lobby below. Pick up the Sea Incense in the middle of the lobby.