>>31000249Sorry, but you're mistaken. On Melemele island, there are some rocks blocking your ability to get on one small island containing one item south of Kukui's lab, and one cave containing one item left of that blocked by rocks. The body of water in the north east of Melemele has nothing. On Akala, there are three places to surf. The southern body on the beach by the hotel has nothing for Sharpedo. The eastern body on the beach by the volcano also has nothing for Sharpedo. The only rocks Sharpedo can break on Akala are a couple in the west by the Wimpod, and all that lets you do is circumvent a double battle you probably did already to catch a Pokemon that probably hasn't even respawned properly.
On Ula'Ula you've got Secluded shore, with nothing, and the water by the ghost trial ground, with nothing. The only place to use Sharpedo on Ula'Ula is the path designed for him to stop you from progressing until you get him. On Poni, there's a beach as soon as you get on the island proper with nothing for Sharpedo. The only place to use Sharpedo is to enter a cave with one trainer and one TM deeper into the island.
That's five places to use it, total. Including small shortcuts.