I think the idea that horizontal space is not short on the ocean and we should use it therefore is a good one.
So the question is how can you take advantage of all this horizontal space without using a lot of construction material to cover it.
I would propose the idea of GRID SEASTEADING which means cover the ocean with a flexible grid of beams at low cost – once you have the wavebreaker effect of the GRID you can use almost any of the discussed island building methods from floating vegetation, to plastic bottles, tiling, whatever, to get additional surfaces, the The SEASTAR PLATFORM is one option for Grid Seasteading.
Numbers are : You get a comfortable floating family home at averagae European and US housing cost, (331 Euro per ton) and you cover a patch of 50m diameter of ocean space for your private use. This is much more “living space” than families have in land based cities.
A “minimum get afloat start up platform” of 6m diameter for the central island – with options for the owner to expand later when the budgets allow – can come with just 9 tons of building material for a 40squaremeter starter home ( cost about 3000 Euro).
I’m working on wave steading. Sea Steads that rest on wave power devices called a salters duck.
The ducks are on truck-like-axles. Free to rotate. The egg cross-section of the duck converts wave action into rotation that are easily handled by axles. Retarding that rotation converts the wave energy into power and creates a wave damped area behind the duck. Most of this energy would be used keeping the sea stead on station (assumes no anchoring but I think anchoring will be possible in deep water: 5 km).
This allows a break wall that is also seatread and factory space.
A ring of these would shelter the interior of the ring. Costs could be saved by making some ducks with minimal decks; open and empty decks. These would damp waves more effectively than most systems at only a small margin of extra cost. The axle bearings etc can be seawater lubricated if the right plastics are used. There is also a system of sea water hydraulics available that would be cheap if mass produced. I need a Lab!
The above graphic image was done in Second Life.
For everyone’s information I was involved with the original Oceania Project in a small way. I’m also in several space organisations. And I have a Degree in sustainable Development, sustainable agriculture and renewable energy,water and sewerage.
If you think a Seastead is like an oil platform, with a couple hundred people within a couple hundred feet of each other, then Surface Area is in short supply. If you think a Seastead is a single family dwelling, then surface area is probably abundant. One more argument in favor of single-family-seasteads.
I agree. I’d much prefer small, artificial islands or seasteads housing a few families or a small community.