A seastead is a structure designed specifically for permanent
living on the ocean's surface. There are many aspects to
designing such structures, including motivation, engineering,
infrastructure, and project planning. The primary motivations
for living on these structures are a desire for political and/or
religious freedom, a more environmentally sound way of life, and
the sheer adventure of it all. A seastead must be able to
withstand strong waves, winds, and currents. We describe
previous attempts at ocean occupation and several possible
designs. Our top choice is based on a hollow vertical tube,
called a spar. A ballasted flotation hull is attached at the
bottom and a living platform is attached at the top. The spar
keeps the hull well below the waves and the platform well above
them. The residents will also require food, water, and energy.
Energy comes from a combination of solar, wind, wave, and diesel
generators, water comes from collected rainwater, solar
distillation, and reverse osmosis, and food from hydroponics and
high density "victory gardens." We advocate an incremental
development model based on niche markets and prototypes, rather
than a single large and financially risky project.