Walkthrough: Connected to the Ancient Poni Path is the Poni Breaker Coast, a small coastal beach that has since been eroded by waves and geysers. You must follow the path to reach both Lillie and Hapu, who are just outside the Ruins of Hope. As you reach them, the three of you will enter the ruins. After a moment at the shrine, Hapu will announced that she has been chosen to be the next Kahuna of Poni Island. She will then suggest you go to Exeggutor Island, an old Trial Site, to find the flute you are looking for. This island can be accessed by talking to the chief of Seafolk Village.
Wild Pokemon:
Chasing Wimpod (Levels 41-44): Wimpod(100%)
Surfing (Levels 41-44): Tentacruel(30%), Lumineon(25%), Pelipper(20%), Gastrodon(20%), Lapras(5%)
Surfing Special Spots (Levels 41-44): Wailmer(70%), Clawitzer(20%), Wailord(10%)
Fishing (Levels 10-44): Magikarp(49%), Wailmer(40%), Carvanha(10%), Relicanth(1%)
Fishing SOS Pokemon #1 (Levels 10-44): Gyarados, Wailord, Sharpedo, Relicanth
Fishing SOS Pokemon #2 (Levels 10-44): Magikarp, Wailmer, Carvanha, Relicanth
Fishing Bubble Spots (Levels 10-49): Magikarp(40%), Wailmer(30%), Carvanha(20%), Relicanth(10%)
Bubble Spots SOS Pokemon #1 (Levels 10-49): Gyarados, Wailord, Sharpedo, Relicanth
Bubble Spots SOS Pokemon #2 (Levels 10-49): Magikarp, Wailmer, Carvanha, Relicanth
Trainers:
Sightseer Jamie - Level 44 Sandshrew, Level 44 Persian
Swimmer Derek - Level 44 Dragalge
Swimmer Kylie - Level 48 Lumineon
Swimmer Ashlyn - Level 49 Lanturn
Items:
TM94 - Defeat Swimmer Kylie & Ashlyn
TM98 - Defeat Swimmer Kylie & Ashlyn
Calcium (Hidden) - Near Southeastern Geyser
Pearl String (Hidden) - Near Ruins of Hope Entrance