Aya at East Akkala Stable needs someone to get rid of the pirates near the coast.
How to Complete the Quest
Glide east to the quest destination to reach the three pirate ships. Defeat all of the Bokoblins, Moblins, and Boss Bokoblin to proceed. You can look in the water between the ships to find wooden logs that you can attach together with Ultrahand to reach the other ships.
After you defeat all of the Monster Forces, a chest will unlock. It contains a Blue Hinox Hammer.
Quest Reward
Afterward, talk to Aya at East Akkala Stable to receive 2 Pony Points and an Endura Carrot.