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This category of designs consists of structures which float directly on the ocean’s surface. Since waves are dangerous, these methods will need to somehow avoid them. We’ll start with options based on modifying existing designs, and move on to more novel ideas.
“A boat is a hole in the water into which you throw money.”
While we have not found any published literature on this concept, it is unlikely that we are the first to think of it. The concept is that a group of like minded people could purchase a bunch of sailboats different sizes and costs and sail around the ocean together. The standard self-sufficiency technologies described later would be used to provide electricity, fresh water, etc.
There are several advantages to this idea. Obviously sailboats are a mature technology, with a large number of types, repair facilities, books and so forth available. They are extremely mobile using renewable energy, and can thus travel all over the world living in “endless summer”. While they are not built for extremely rough seas, they are mobile enough that with advance planning they should be able to avoid such situations. And a fleet of sailboats is both modular and scalable. They can even grow some food, as described in Sailing the Farm Neumeyer1982. Unfortunately, there are serious drawbacks.
Boats tend to be built from expensive materials, and are costly to build and maintain. They are optimized for movement, so they have have small deck areas (tough for solar panels and greenhouses) and cramped interiors (tough for living in). Nor are they particularly comfortable in significant waves. The marketing/publicity angle is more difficult because it doesn’t seem like a new way of life. We cover these problems in more detail in the FAQ question Why not just buy a boat?.
There are definitely some nice aspects to a fleet of sailboats, such as not having to design a new structure. It would be a relatively easy way to start living on the water, since there are people already doing it. But boats are designed to travel from place to place across the ocean, not to live in. The difference between a sailboat and a seastead is like that between a house and a car. Sure, you can live in a van or RV, but it’s just not that comfortable. The residents would be more wandering nomads than permanent settlers. There is nothing wrong with this lifestyle, but it’s not what we think of as true seasteading.
Many people have suggested that rather than designing a unique structure, seasteaders could just purchase and retrofit a large used vessel such as an oil tanker or cargo ship. Again, the standard self-sufficiency technologies would be used to provide infrastructure. As evidence that big boats make decent floating cities, we need only look at the cruise ship industry. One way to think of this concept is as a low-budget, do-it-yourself cruise ship.
Obtaining a used boat would reduce costs, and it would already contain many useful systems like propulsion and navigation. The propulsion could be used occasionally, although the ship would mostly drift to conserve fuel. Large vessels are less responsive to the waves than small ones and so more comfortable to be on during storms, as well as safer.
Unfortunately, large boats are not exactly scalable, so it would take a sizeable initial group to purchase one. They are also not reconfigurable or modular (although an assembly of multiple ships would be). They have many of the same drawbacks as sailboats, like limited solar area and not seeming like a new way of life. We’ve basically traded modularity and low starting cost for seaworthiness and some interior volume, without really gaining any ground. Like the sailboat fleet, the idea certainly has some merit, but we don’t think it’s the most promising option.
Some of these issues can be addressed with a hybrid combination of a cargo ship and some of the platform types described below. The cargo ship would take the materials to some remote island or atoll, and the colony would be deployed. In the event of political problems, bad weather, or simple boredom, the colonists would load everything back onto the boat and move someplace new.
In waters that are naturally calm or somehow protected, there are many simple systems that can be used to turn water into land. Each consists of some sort of buoyant foundation on which to put whatever structure is desired. While we’ll be recommending a different approach, this one is quite promising as well. In an area without large waves, it would be quite cost-effective, and should be strongly considered as an alternate design.
One of the simplest systems was suggested by Wayne Gramlich in his original seasteading paper [Gramlich1999]. It utilizes plastic 2-liter beverage bottles, which are extremely common, incredibly cheap, and resistant to sea water. These bottles can be banded together into hexagonal grids of 7 bottles each. The grids are then stacked and layered to form a buoyant lattice. Alternatively, one can use Rich Sowa’s method of filling nets with the bottles. Some sort of rigid surface then needs to be placed on top of the flotation.
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Another simple technique is to have an inverted cylinder, open at the bottom, containing air. This idea was used by Sea Structures Inc. for their SeaCell system [SSI]. A disadvantage with open containers is that as depth increases, the air is compressed and displacement goes down. This flotation is cheap to manufacture, and can be stacked for easy transport. Again, some sort of rigid platform needs to sit on these cells.
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Yet another simple method is concrete slabs such as those manufactured by IMF [IMF]. These are hollow boxes of reinforced concrete, with enough buoyancy from the interior airspace to support the concrete as well as a structure. IMF’s designs include shock-absorbing connectors, integrated structural cleats and pile rings, and integrated utilities. Because the structures are monolithic and sealed, they cannot take on water and are unsinkable unless broken. And ferrocement is cheap. Most floating homes in the USA nowadays are built on such slabs. They’d be fairly easy to connect to one another, and small ones could be easily built onboard. We think this is the most promising aquatory technology for protected waters.
One interesting possibility is the PSP designed by Float Incorporated [FloatInc]. It consists of a number of inverted hollow cylinders, as described earlier, but with a clever addition. Imagine what happens as a wave rolls under these cylinders. The water in each cylinder moves up and down, and the air pressure in the trapped airspace changes. In a PSP, these spaces are connected through pneumatic lines and valves, so that these pressure changes result in air moving between cells. This dampens the waves and distributes their force so as to reduce peak load on the structure. If air turbines are attached to these lines, it becomes a wave-powered electricity generator.
The PSP has some characteristics of a platform (it can support loads) and some of a breakwater (it attenuates waves). It is built out of concrete, our favorite construction material, so it’s relatively cheap. it’s very modular and fairly reconfigurable. Cost estimates are $5M - $7.5M an acre ($115-$160/ft2 in the open ocean. However the inventors have not been able to find a major purchaser, so this is an unproven technology. We have some concerns about the design’s ability to withstand (or block) severe storms, with waves large enough to wash over the edge of the platform. Still, it is a promising system.
{ this section could use some trimming - P }
The ideal seastead technology is safe, inexpensive, and modular. Here we’ll consider whether structures built out of converted freight containers qualify.
The shipping industry has been revolutionized by these containers. Freight containers can be moved between trucks, ocean freighters and trains without requiring that the container contents be changed. Their popularity has made them cheap and plentiful. Used 40 ft freight containers can sometimes be obtained for less than a thousand dollars. A similar alternative is large propane tanks, which are much stronger because they’re built to hold pressurized gas. They cost several thousand dollars (used), but this may be worthwhile for safety.
The table below summarizes a number of common container sizes:
Container Length
(ft’in”) Width
(ft’in”) Height
(ft’in”) Volume
(ft3) TARE
(lb) Payload
(lb) Max. Gross
(lb)20’ Dry 19’10.5” 8’ 8’6” 1,173 5,160 47,740 52,900
40’ Dry 40’ 8’ 8’6” 2,391 8,730 58,470 67,200
40’ Hi Cube 40’ 8’ 9’6” 2,692 9,150 58,050 67,200
48’ Domestic Dry 48’ 8’6” 9’6” 3,463 9,700 57,500 67,200
53’ Domestic Dry 53’ 8’6” 9’6” 3,830 10,280 56,920 67,200
Since the weight of 1 cubic foot of water is 62.4 lb., a sealed container can generate a substantial amount of bouyancy. For example a 40 foot high cube container generates 62.4 x 2692 - 9150 = 158,831lb or almost 80 tons of bouyancy.
Since freight containers are not designed to float, some effort must be expended to convert them. The basic concept is to weld all holes and vents shut, along with the access doors, and to install a seaworthy access port. It must also be sandblasted and coated with seaworthy paints. It may need some structural reinforcement, as the corrugated steel skin is not meant to withstand much force.
Once the container is seaworthy it is ballasted on one end to force it into a vertical orientation with 1/2 to 2/3 of the container submerged below the water line. This reduces interaction with waves. In a storm with large waves, the structure will basically move up and down with the waves with relatively little rocking motion. Because it’s small enough to bob, it doesn’t absorb much wave energy. In addtion, by submerging a significant fraction of the structure below the water line, there is less swaying due to high winds. This is similar to Marc Piolenc’s spar buoy. In a severe storm, the occupants of a container will definitely be pushed around. However, as long as everything is properly secured inside the container, about the worst that will happen is a severe case of sea sickness.
Even though the freight container should be relatively safe in pretty severe weather, it is still prudent to plan on situating freight container seasteads in areas that do not often experience severe weather. It is further prudent to have a means of moving a freight container seastead out of the way of an approaching severe storm. A basic outboard motor should provide the means to move a modest distance even though a freight container is hardly shaped for optimum traversal through water.
One nice characteristic of this design is that it can be easily purchased, stored on inexpensive property during conversion, converted, and then shipped off to an ocean deployment location. Freight containers are designed to be moved around, so it is relatively easy and inexpensive to do so. Ballasting may need to weight until the final site, as it will make the container heavy and unbalanced.
Since it’s oriented vertically, we can divide the container into floors. Assuming a 40 foot container on end with approximately 8’ ceilings yields 5 floors. The bottom floor will be partially occupied with ballast, so it should really be thought of as a cramped storage compartment rather than a full livable floor. Using a 48’ container provides an additional floor and a 53’ container might provide two additional floors. Since the dimensions are 8’ by 9.5’, each floor is 76 ft2. This is not luxurious, but for some people it will be adequate. The total area of 300 ft2 actually compares favorably with the floor area of a sea worthy sail boat. For more space, multiple containers can be welded together into larger units.
Giving the limited top deck area, we need some creative solutions to provide an adequate supply of food, water, and power. Just like the larger structures we’ll propose later, there is no reason why a container seastead can’t have a cantilevered upper platform to provide additional solar area. During bad weather, anything kept up here can be stored safely inside. Another simple solution is to tether inexpensive inflatable floats to the seastead. These could support [solar stills][], PV panels, and small greenhouses. Again, in bad weather these are deflated and brought inside.
The primary reason to think about freight containers is to propose alternatives that further lower the cost of bootstrapping seasteading into existance. Will a freight container seastead be as safe in severe weather as one of its larger cousins? Almost certainly not. However, it is probably safe enought that it can seriously be considered as a potential start. As the seastead community gets larger, the need for this design may well diminish as people switch to structures designed specifically for seasteading. Thus, freight container seasteads should really be thought of as a bridging technology between what is available now versus what we can build eventually. Alternatively, they may continue on as low-income housing, much like trailer homes on land.
“Any structure or contrivance to break the force of waves, and afford protection from their violence.”
A simple example of a breakwater is any island or reef, which acts as a natural barrier for its lee shore. Artificial breakwaters can be seen surrounding the entrances to any marina, usually consisting of concrete piers or piles of rock.
The advantage of using a breakwater is that it eliminates all the problems caused by waves. Structures become much cheaper, safer, and easier to expand, seaplanes can land and cargo is easier to offload. But to do this, you must dissipate the tremendous energy found in ocean waves, and do it continuously, for years on end, even during severe storms. If the breakwater fails, suddenly your structures must face waves they were not designed for, which may be disastrous. We’ll outline a number of the different methods that could be used to build such breakwaters. Later we’ll explore the question of when this is the best way to deal with waves.
TODO: Add lots more here. Breakwaters are really important - they get us massive cost decreases which are essential to making a country, not just a single fancy hotel or business park. Add Patri’s idea for inclined plane breakwater (hopefully cheap).
Any landmass which reaches close to or above sea level acts as a natural breakwater. Rock is tough stuff, and it takes quite awhile for the ocean to grind it into sand. There are basically two options: we can shelter by a large landmass (which will almost certainly be inhabited), or a small one. Large landmasses have political difficulties, as we will be fairly close to existing nations. It is difficult to be protected on all sides yet still be in international waters. Still, there are some possibilities if we are willing to accept moderate waves, such as seas like the Mediterranean.
Smaller breakwaters include atolls, reefs, and seamounts. An atoll is a special class of island that is formed when the ocean has worn a volcanic peak down to a roughly circular shape. As a result, they basically consist of a breakwater surrounding a calm lagoon. Because so many islands are volcanic in origin, atolls are quite common, and many are uninhabited. One of the more famous is the Bikini island atoll in the Marshalls, where the US conducted nuclear testing [Bikini]. These lagoons range in size from tens of thousands of acres down to almost nothing.
Yachtsmen, encountering unexpected storms, have weathered gale-force winds by anchoring in such lagoons, so atolls definitely act as a wave barrier [Fisher1985, p. 52]. Unfortunately, the fact that atolls contain land means that they are all claimed by an existing country. While an abandoned atoll could doubtless be used for awhile before anyone noticed, our goal as seasteaders is to create a stable way of life. We want to be pioneers, not outcasts. This renders claimed atolls unsuitable for frequent use.
The obvious solution is to look for submerged atolls or reefs, which do not count legally as land. After all, a breakwater does not need to extend above water to provide significant protection, it need only come close. These submerged reefs and rocks, formerly only known as hazards to navigation, can be used to protect our new way of life from the elements. While the Minerva incident indicates that nations do not always respect these rules, our chances are much better if we follow them.
Unfortunately, suitable geographic features are likely to be rare. Any rock above water creates a zone of 3-24nm around it of sovereign waters. So we need a reef which is not within that distance of any above-water reef. It can’t be too far below water, or it won’t be a useful breakwater. So we need an area where the reef comes quite close to the surface, yet never rises above it, and the odds are against this happening.
An additional advantage to such natural breakwaters (if we can find them) is that they provide for cheap and easy anchoring. Also, they are likely to have pretty underwater scenery. A disadvantage is that the colony is tied to one physical location, which means that it cannot easily avoid political problems, move with the seasons, etc.
An alternative to finding a submerged breakwater is to be close enough to some appropriate landmass that it can be used for shelter during severe storms. While the waters would be legally controlled by another nation, the use would only be occasional and it’s unlikely that anyone would be paying attention. Still, satellite photos could be used later as part of some legal maneuver. In an emergency this solution is fine, since any court is more forgiving than Davy Jones Locker, but it seems a poor idea to depend on it.
Artificial breakwaters have a long history of use to protect harbors, marinas, and coastlines. There are numerous breakwater designs, and they are fairly simple in principle, so we won’t cover them in detail. Most rely on big pieces of concrete, although there are many alternative methods. Most designs are meant to rest on the seafloor, or at least be tethered to it. While this is fine for shallow water (perhaps on a seamount or reef), it won’t work in any significant depth. Hence we need a floating breakwater.
Ocean waves can be very large, hence a traditional design would need to be very large. Rather than absorbing all the energy, perhaps we can simply get it to dissipate harmlessly. This may sound difficult, but this can be seen on any beach with a wave break. The incoming waves, reaching shallow water, begin to pile up. They reach an unsustainable height, form the familiar whitecaps, and break, collapsing on themselves. Only a gentle wash reaches the shore. The soothing sounds and pretty patterns on the sand are all that remain of the wave’s energy.
This effect could be simulated by submerging a long triangular breakwater. As waves reach it, they will pile up and eventually break. This breakwater does not need to be particularly strong, because this aikido-like method never takes the brunt of the force. Still, it will need to be be quite large, and will not be cheap or easy to build.
Any non-anchored breakwater will be steadily pushed by the waves towards the center colony, so the two must be strongly connected. Many breakwater designs such as the simple concrete wall, the aikido breakwater, and the PSP could be used in such a configuration.