Libertarians dream of living on a floating city with no government regulation but there are some challenges.
Seastead designs tend to fall into one of three categories: ship-shaped structures, barge-like structures based on floating pontoons and platforms mounted on semi-submersible columns, like offshore oil installations. Over-ordering by cruise lines means there are plenty of big, second-hand liners going cheap. Ship-shaped structures can pack in more apartments and office space for a given cost than the other two types of design, but they have a big drawback: their tendency to roll in choppy seas. Cruise ships can sail around storms, but static seasteads need to be able to ride them out. And the stabilisers on big cruisers only work in moderate seas and when the ship is moving.
About those engineering challenges
Pontoon-type structures, or giant barges, are the cheapest of the three options, but they are even more vulnerable than ships to choppy seas. Shipbuilders like Mitsubishi Heavy Industries of Japan have proposed various designs for floating cities based on massive â€œmega-floatâ€ pontoons, with skyscrapers towering above the waterline. But these would only work in calm, shallow watersâ€”and these tend to be within land-based governmentsâ€™ territorial limits. George Petrie, a former professor of naval architecture at the Webb Institute in New York state who is writing a series of technical papers for TSI, has calculated that even in a relatively benign stretch of water off Hawaii, such structures would leave their residents pretty groggy much of the time.
As oil companies drilling in ever deeper waters have demonstrated, structures built on floating columns are the most rugged, though they are more expensive than ship- or pontoon-type vessels. The shipbuilding industry has plenty of experience in making them, but the expectations of comfort among the permanent residents of a seastead will be much greater than on an oil platform, where workers are paid well for short tours of duty in relative discomfort. Even in placid weather, floating-column structures bob up and down as the sea heaves beneath them, which can make people seasick. To prevent the vessel from drifting due to currents and winds, seasteads may need dynamic-positioning thrusters, but these would increase costs. In waters less than 1,800 metres deep, Mr Petrie calculates, a cheaper option would be to moor the platform to the seabed. As it happens, there are a number of barely submerged islands off the coast of California, the location of preference for early seasteaders. Alas, they tend to be volcanoes.
Even once a viable blueprint for the structure of a seastead is produced, the technical challenges are not over. The more it relies on land-based supplies of fuel and water, the harder it will be to achieve the libertarian dream of escaping the evil ways of existing governments. At sea there is plenty of wind and wave energy, and occasionally sunshine, but building renewable-energy systems that can survive harsh ocean conditions is even harder and more costly than designing land-based ones. Another problem is communication. Satellite-based connections are slow and expensive. Laying a fibre-optic cable would be difficult. A point-to-point laser or microwave link might work, suggests Michael Keenan, the president of TSI. But that would rely on a land-based transmitting station, again making the seastead reliant on landlubbers.
I just canâ€™t see this turning out well.