The Fish for Jade quest in Genshin Impact involves a bit of swimming, but the bigger issue for many players is figuring out how to even begin the quest. This world quest is actually locked away behind one of the story chapters.
To get the Fishing for Jade quest to populate in your game, you will need to finish Ganyu’s story quest, Sinai Unicornis. You will need to access this from the quest screen using a Story Key. Story Keys can be earned by completing daily comissions.
Once you have access to the quest, make your way to Liyue Harbor and look for Kun. If the the quest is active, he will be marked by an exclamation point. Kun will be on patrol on the main dock.
Kun will tell you that some boxes from a shipment have been lost in the harbor. One of them was quite important as it included an item for the Jade Palace. As long as you are tracking the quest on the quest screen, you will be led to the water near the main harbor. You need to jump in and swim to the five boxes, interacting with all of them. It is easier to just teleport out to the point in the south of the town for the next section.
Once again, follow the marked path to the water, jump in, and grab all the boxes. One of them will contain a parcel that you need. Bring this back to Kun and he will ask you to deliver it to Baiwen at the Jade Palace. Just follow the path marked on the ground to get to her. She will thank you for delivering it and that will wrap up the mission.