Following the usage of nuclear weapons during World War 3 several hundreds of vessels found themselves lost on the seas. With no families or homes to go home to they eventually formed the Blue Fleet.
Eventually, after travelling for nearly three decades of years, the Blue Fleet used its pool of salvaged resources to refurbish a cluster of oil platforms turning them into a sprawling city complex.
While the original founders are long since dead Rig City, as it is now called, continues to grow and welcomes all people of Earth as long as they follow one simple rule:
Today Rig City remains as a neutral meeting ground, city and massive marketplace all hosted onboard the many docked cargo vessels, cruise ships and oil rigs.