The higher Guild levels don't have that many Rewards which make the work required to reach those levels worthwhile. Adding more amenities or enough hooks on the largest ship (the Typhoon) to add all available amenities would increase the benefits of being a very high level Guild. One new airship amenity could be a Death Ward shrine whose effect could not be dispelled by a Beholder or similar mob. A Death Ward buff which lasts for one hour would be very useful and further incentive to each the 85+ range among Guild levels.