Ledo at East Reservoir Lake needs help getting a blue stone from the cave to the northeast.
Quest Location
Talk to Ledo at 3595, 0342, 0211, in the northwest part of East Reservoir Lake, southeast of Zora's Domain.
How to Complete the Quest
Use the nearby wooden boards and fans and steering stick to make a raft, then go northeast to the cave that Ledo showed you: Reservoir Lakefront Cavern. In the southeast part of the cave, you find blue stones on the ground. You only need one. Attach one to your raft, turn the raft around, and go back to Ledo at the quest destination on the map. Place the blue stone in front of Ledo and stand near him to complete the quest.
Quest Reward
Ledo gives you the Zora Fabric.