The first seastead happened fifteen centuries ago. The result was the most beautiful city in the world, Venice. People who were sick of their violent governments fled to the water, where they built civilization on stilts. That startup society - a free city-state on the water - became so successful it dominated the Mediterranean for a thousand years.

Seasteads are man-made islands that float permanently on the ocean with any measure of a political autonomy. They would essentially be startup societies where people could form whatever kind of community they wanted.

Seasteads are a technology for anybody to form an alternative community based on their unique values - for communities to organize themselves however they want. Seasteads are their chance to demonstrate their vision can work. All that matters is that people can create, join, and leave seasteads voluntarily. As long as people can choose among seasteads, the best ways of living together will prosper, and the ones that people don't like will fail.

I think our children will be living on floating cities, and they will look back on the 20th Century, when people lived in primitive governments founded in previous centuries, and they will be living on modular, sustainable, floating cities that we can't imagine now, that are based on the voluntary choice of citizens. I think we will have a marvellous world in the 21st Century.

Seasteading could be the means by which humanity will live sustainably.

That's the marvellous thing about seasteads; if a government fails, there's nothing much the people who live there can do about it. But if seasteads fail, they simply disassemble and go away.

Nearly half the earth's surface is unclaimed by any country, so seasteads would be startup countries on the blue frontier. Patri Friedman is a Google engineer and theorist of political economy who realized that if society floated, it would completely change the nature of governance itself. If seasteads are modular and can be moved about, allowing people to choose new societies, we'd create a market of governance providers, competing to attract residents.