Experience is needed for crew members, including the captain, to level up.
When the captain levels up new furniture, clothing, accessories, and other items may be unlocked.
Lorna Crabhoarder gains experience by catching fish.
John Swiftblade gains experience by defeating monsters.
Etta Cornelius gains experience by identifying artifacts.
When the other crew members are ready to level up he/she needs to go the the appropriate upgrade cabinet for 24 hours.
Lorna Crabhoarder uses the upgrade cabinet at the Fishing Academy.
John Swiftblade uses the upgrade cabinet at the Warrior Academy.
Etta Cornelius uses the upgrade cabinet at the Accordia Library.