Leviathan

Leviathan is the infamous floating pirate haven that sails throughout the Cerulean Ocean. It is made from the amalgamation of hundreds of ships, both pirate ships and trade and military vessels that have been captured throughout the ages. While the city itself does not attack any ports, it is capable of chasing down and destroying any unfortunate vessel that should cross its path. The city functions both as a safe port for pirates to dock and unwind without fear of arrest while also acting as a pseudo government for the lawless seafarers. However these laws usually only extend so far as to make sure pirates who are members of Leviathan don't fuck with other Leviathan pirates. Leviathan also runs the occasional protection racket, making ports and traders pay them if they want to keep Leviathan pirates away.

The city is built to resemble an enormous hydra, with each of the heads of the hydra controlled by a different powerful pirate captain referred to as the Heads of Leviathan. A Head of Leviathan is never elected, they must simply earn the role indisputably and also work to keep it from the other ambitious pirates that might seek their position. The main jobs of the Heads of Leviathan beyond managing their own crew is chooses which pirate crews get to be a part of Leviathan, which jobs they get to take, and making sure the city doesn't sink.