Pokémon Ruby and Sapphire/Route 106

Route 106 is, more water, and more trainers.

Items

 * Heart Scale - hidden on the water's edge, southeast of the signpost
 * Stardust - hidden on a rock, northwest of the signpost (available earlier when you were in Dewford Town)
 * Poké Ball - hidden on the water's edge, northeast of Fisherman Elliot (available earlier when you were in Dewford Town)
 * Protein - western-most part of the shoreline

Trainers

 * Swimmer Nicole
 * Swimmer Douglas
 * Swimmer Douglas

As soon as you can, get to the sandy beach to the south, because after Douglas there isn't anything interesting in the water. There is, however, a Protein on the beach.