The Northern Seas (北の海 Kita no umi) refers to the ocean that surrounds the Gold region of Sentora. Not far from Gold Port, these waters are ruled over by Poseidoness, guardian of the Silver Orb. It is also where Captain Selene’s Ship is found, just about a week traveling length from Gold Port. These waters are notably more dangerous than the southern counterpart, as they are much closer to Hellgondo.
After Alice informs Luka of the purpose of the Silver Orb, Luka sets out to find it. He defeats a Dagon en route before encountering Poseidoness, who accuses Luka of a thief, but was actually warned by Kraken of his arrival beforehand and wanted to test him, and hands over the Silver Orb.
Luka later sets sail with the ghost of the famed pirate Selene, posing as a supposed granddaughter named Selena, to her deserted ship where she accidentally opened the Calamity Box and unintentionally released the Beelzebubs before perishing. There, Luka and Alice fight the monsters, obtain the Purple Orb, and bring peace to Selene’s and her crew’s spirits.