SeaCity

Seacity is a term used to describe a city located at sea, either on floating structures or on submerged or offshore platforms. In urban planning and speculative design, seacities are envisioned as self-sustaining communities that can house residents, support commerce, and deliver public services with minimal land use. They are proposed as potential responses to rising sea levels, coastal crowding, and resource constraints, as well as to explore new governance and economic models.

Design concepts emphasize resilience and modularity. Floating platforms or offshore modules may be tied together by flexible connectors, with buoyant hulls and advanced ballast systems to withstand storms. Energy and water self-sufficiency are pursued through solar, wind, and wave energy, desalination, and aquaculture. Transportation links to shore or between modules, and waste treatment, recycling, and vertical farming networks, are integrated to reduce environmental footprint.

Governance and economics vary by proposal. Some models imagine special legal charters or sovereign-like jurisdictions operating in international waters, while others rely on augmented public-private partnerships or island-city agreements. Economic viability depends on construction costs, operating efficiency, access to capital, and potential revenue streams such as research facilities, tourism, offshore services, and residencies for scientists or entrepreneurs.

Challenges include legal status, safety standards, environmental impact, and long-term maintenance costs. Real-world progress has been incremental, with pilot demonstrations and concept studies rather than full-scale seacities. Notable efforts include floating-city proposals by advocacy groups and corporate concepts in speculative designs. Related topics include floating city concepts, seasteading, and ocean energy infrastructure.