Kitsune Island

Kitsune Island is a sea event that spawns exclusively in the Third Sea. It holds the Kitsune Shrine, which gives exclusive rewards in return for Azure Embers. To spawn it you need three things: Sea Danger Level 6, a Full Moon and any boat. You can sail into Danger Level 6 in the daytime and wait for the Full Moon, or stay in Danger Level 5 and only cross into Level 6 when the moon rises, without waiting more than about five minutes. The boat's owner must be sitting in the boat, and if you use another player's boat the island will not spawn. Only one Kitsune Island can exist per server, so whoever enters Level 6 first spawns it. It usually appears if you enter within 25 seconds of the full moon message and disappears after 15 minutes, though it will not despawn while players stay on it. The wiki advises starting the hunt right before sunset, because starting early can trigger another sea event. Rough seas make collecting Azure Embers harder, since lightning can knock you out of held mobility moves, so use quick dashes such as Yama Z and X, Lightning F or Godhuman Z and C.