Where to get a luxury ball in Pokemon Emerald?

You need to have a Pokemon with move SURF and DIVE to do this... First SURF to Route 108 (between Dewford Town and Slateport City) 'til you find an Abandoned Ship and enter it... Next go to the cabin inside the ship where there is a deep part of water, use DIVE and move underwater 'til you find a shiny part in there then move up... There you will see six cabins... One of the cabins has Luxury Ball...