You will need an Acro Bike to reach it. Venusaurite Venusaur Under the restoring house on Route 119 after the legendary battle in Sootopolis.

On the shore is a Super Repel. This route has five different Pokemon trainers along the ocean path. They are all listed below. The first is near the shore, the next two are on the north side ...

both of which increase the liklihood that you'll find a wild Pokemon when you fish. You can find a gulpin on Route 110 with the sticky hold ability or head to the Battle Resort and use a super rod ...