(Everyone is assumed to be on the boat, we need to move on.)
The boat set sail and after aprox ten minutes, arrived at Slateport's beach. At the Pokémon Center, Liam overheard on the TV that a minor earthquake had happened in Vendenturff, delaying its contest. So, Slatepot's was pushed forward and it would be out on the beach. Entry into the contest would be at Slateport's Pokémon Center. When Joy returned, he registered for the contest, after contacting Prof Oak to make sure he had the Pokémon he wanted to use for it.