Most of the Ocean’s life clings to the shallower water over the continental shelves. That is where the food supplies are found. The middle of the ocean tends to be a desert, with only scant sea life to be found. This is one reason why ocean “fish farms,” or aquaculture, are located near shore, over continental shelves.
Cold Deepwater Nutrients Key to Fish Populations
For obvious reasons, the ocean’s cold deepwater contains most of the sea’s nutrients. Wherever the cold deepwater thermohaline currents are forced upward, great schools of fish will feed, breed, and multiply. This is why fishermen go to the “banks” and edges of continental shelves, where deep rich water is forced upward from below to feed the hungry multitudes above.
Mid-Ocean OTEC Pulls Rich Deepwater to the Surface
Ocean Thermal Energy Conversion (OTEC) pulls cold, rich seawater to the surface — making use of the temperature differences between deepwater and tropical surface water to generate electricity. But OTEC would provide a mid-ocean seastead with far more than electricity. OTEC also provides cold water for air conditioning and freshwater condensation, and the rich nutrients of the deep seawater for aquaculture — growing lots of fat fish in the ocean desert.
Consider a Barebones Seastead
Initially, a barebones seastead is little more than a floating breakwater, with a motley assortment of small live-aboard yachts in the sheltered artificial lagoon, along with simple floating platforms for small businesses. Initial populations will be mostly transient, as curious cruising yachtsmen stop by to check things out, perhaps topping up on fuel, water, and supplies.
But early on, ventures such as OTEC aquaculture and energy would provide a much-needed expansion of the seastead’s infrastructure — fresh fish, electricity for sale, abundant freshwater from condensation, and cold seawater for cooling purposes. The freshwater would be used not only for drinking, but also for growing fresh food crops.
Best Locations for OTEC
OTEC requires as large a temperature differential between deepwater and surface water, as possible. The image above provides a general idea of global temperature differentials for purposes of OTEC.
Even at its best, OTEC is not particularly profitable unless it is utilised in an isolated location, where fuel supplies and food must be imported at prohibitive prices.
In fact, a mid-ocean seastead is one of the few locations where OTEC would be worth doing. Efficiencies would not justify the initial expense virtually anywhere else that humans might live in numbers.
Seastead aquaculture would be possible without OTEC, of course, but the nutrient supply would be a limiting factor for local fish swarms. Effluent from minimally processed human waste and organic garbage, for example, could supply a small amount of nutrients to a small fish farm. But the steady rich supply of pumped deep seawater from OTEC would provide for a much larger aquaculture crop.
Early “Experimental” Seasteads Need to Evolve
Many human artifacts tend to thrive only after having evolved over time: Languages, forms of government, cities, networks of infrastructure including transportation and pipelines, etc. Mid-ocean seasteads — given their novel nature — would also need to evolve from simple beginnings.
It would seem that a reliable floating breakwater — with its artificial shelter for boats and other floating structures — is as bare a beginning as possible for a mid-ocean human settlement. But it also seems clear that the OTEC technology is almost a perfect fit for an isolated seastead, if OTEC can be optimised to the scale and location needed.
Other technologies are likely to be invented or discovered through serendipity for use in remote seasteads. Entrepreneurs may build floating hotels in the sheltered lagoon, for example, and fly tourists in to see the novel settlement via sea planes or float planes.
A number of different types of personality might be attracted to visit the seastead, including libertarians, greens, adventurers, ocean cruisers scouting out potential refueling/resupply locations, journalists looking for a story, and inquisitive entrepreneurs who are interested in possibly building their own seasteads.
Moving from Potential to Potential
The more conventional approaches to “seasteading” do not actually look to the mid-ocean deep sea environment to build a settlement. The challenges are too daunting without reliable storm protection.
The first step to building a safe and durable mid-ocean settlement is to create a space sheltered from the worst effects of ocean storms and waves. Once that is accomplished, the potentials begin to unfold, one on top of the other.