Debris

A city of flying wood. Chained neatly to a coral reef far below the city is an exceptionally beautiful location despite its makeup of many different ships. A huge coral column extends upward out of the water to the island as well. The island leaders keep people from living on the column, keep it clear and safe, really their only required duty as many are unsure if the city would stay afloat if it broke.
The secret to flying islands in the region is utilized by the city's leaders to make their ship island float.

City of Debris mark one map

the city is a famous Kleptocracy where backstabbing, bribing, and thievery are the same as voting. Huge rivers float up chains to the island that allow sailing ships to sail up them live rivers, carefully, and land on the floating waters that gather around the island like giant bubbles and domes of water.