Ep. 31: The Island Whisperer!

31

Olivia, the Akala Island Kahuna, and her Lycanroc appear at the school just in time to stop a fight between Kiawe's Charizard and a Tauros. She completely wins over everybody's Pokémon, including Litten. The class and Professor Kukui will be traveling to Akala Island for a special practical class under Olivia's supervision. On the way, they encounter various types of Sea Pokémon. After Ash and Pikachu join Olivia in an underwater swim, they find a Wailmer trapped in a rock crevice by a vicious Bruxish. Now they have to help the Wailmer and fend off the Bruxish at the same time. (Source: Wikipedia)