` SeaSteading -- Homesteading the High Seas

This is one of my miscellaneous projects. Like most of my projects, its status is work in progress.

SeaSteading -- Homesteading the High Seas

Table of Contents


A low cost approach to colonizing the ocean surface is examined. Flotation is accomplished using thousands of recycled 2-liter carbonated beverage bottles. Food is grown using tried and true `victory garden' style gardening, rather than advanced hydroponics. Power generation is performed via a combination of photovoltaic, wind, and wave energy extraction rather than sophisticated OTEC (Ocean Thermal Energy Extraction.) The net result is a system that can be developed and deployed for without expensive R&D, thereby reducing risks and increasing investor confidence.


Why would anyone want to colonize the ocean surface? There are a number of reasons -- adventure, religious freedom, tax avoidance, trying out new forms of government, etc. Of the ones listed, tax avoidance is my pick as the most powerful motivator for the development of sea surface colonization technology.

In my meanderings around the Web, I have run across three organizations that are discussing the possibility of colonizing the ocean surface -- the Atlantis Project, the New Utopia Project, and the Millennial Project (now the Living Universe Foundation.) There are probably others, but these are the ones I have encountered so far. Both the Atlantis and New Utopia project appear to be in the `trying out new forms of government' camp. The Millennial Project is based around the concept of colonizing the ocean surface as the first step towards colonizing the galaxy as described in Marshall Savage's book The Millennial Project: Colonizing the Galaxy in Eight Easy Steps [Savage1992]. It is my personal opinion that these efforts will fail because they are currently structured as fairly big and expensive projects that will have a very difficult time attracting the requisite capital. I claim that it is difficult to raise millions of dollars in capital, when an investor has the opportunity to invest their money in the current hot area (as I write this -- Internet stocks) and double their money in six months. I would be delighted to be proven incorrect in my prediction.

This paper proposes a different strategy to achieve the colonization of the ocean surface. By way of analogy, the western territories of the United States were not colonized by a few well financed colonization efforts, but instead the west was colonized by tens of thousands of more individualized efforts. One of the primary ingredients was the Conestoga wagon technology. The Conestoga wagon was affordable by individuals and allowed them to successfully take their possessions to their eventual destination. In the discussion below, I intend to outline some technology that is within the financial means of individuals and would allow individuals to colonize the ocean surface, rather than large colonization corporations. I call this technology a seastead, for `SEA homeSTEAD'.


I currently live in the United States and it is at this time a very litigious society. As I have read up on ocean technology, I have gained a very healthy respect for the ocean and how dangerous it can be. If you decide to do any of the things mentioned in this paper, be sure to do your own independent research to decide how dangerous the activity is. I assure you that I have no intention of living in the middle of an ocean without first verifying that my flotation device can withstand some serious ocean storms. I recommend that you take similar precautions.

I do not guarantee any of the technology presented in this paper. If you decide to build any of the technology presented, you do so at your own risk and I am in no way liable for what happens to you or your equipment.


Before you can colonize the ocean surface, you need to prepare the surface for your arrival. Ultimately this task involves producing some artificial land. The basic concept is you need to put your land on top of something that floats; otherwise, you are colonizing the ocean floor, which is a completely different engineering task!

Flotation is based on Archimedes principle that buoyancy is created by displacing water. A boat accomplishes this task by having a water tight shell that displaces the water as shown below:

Floating Boat
The amount of buoyancy is equal to the total weight of the displaced water.

As I researched the topic, I discovered that the concept of artificial islands has been around for quite while; indeed an entire chapter is devoted to the concept in chapter 7 of The Future for Ocean Technology [Ford1987]. Basically, the artificial island technology to date is based on barge technology. You take a large shell and cover it. The problem with barge technology is that it is not particularly cheap.

The Atlantis Project is based around Sea Cell (tm) technology. A rough diagram is shown below:

Sea Cell
The Sea Cell (tm) concept is based around an air tight shell that is inverted to displace water. Again, the amount of buoyancy is equal to the total weight of displaced water. One of the big problems with the Sea Cell (tm) technology is that it is patented an thus has to be directly obtained from the patent holders. This particularly annoying since the patent holders are having a difficult time raising the capital needed to go into serious production. Thus, even if you wanted to use Sea Cell (tm) technology, you might have some serious difficulty getting delivery of them.

The Millennial project wants to build their flotation devices out of an interesting material called seacrete or seament. This fascinating material is manufactured directly from the dissolved minerals in sea water by passing an electrical current through a mesh immersed in the water. Since the one of the goals of the Millennial project is to use locally produced materials whenever possible, the desire to use seament is quite consistent. However, if your goal is just to live on the surface of the ocean with as little investment as possible, seament may not be the most economical material to use. Seament requires a lot of electricity to manufacture. The Millennial project assumes that OTEC (Ocean Thermal Energy Conversion) will provide the requisite amount of power; unfortunately OTEC is still fairly early in its development cycle, so its economic viability have not yet been demonstrated. If you are using an alternative form of energy (e.g. photovoltaic, wind, etc.), the cost of seament will be quite high. I think most seasteaders will opt for less expensive flotation solutions if they are available.

The flotation method I describe below uses thousands of recycled 2-liter plastic beverage bottles. A cross section of 2-liter bottle is shown below:

2-liter Bottle

Plastic beverage bottles have a number of advantages:

Large numbers of the bottles are simply thrown away. They can be yours for free if you simply agree to haul them away. Many states/communities have recycling programs where the bottles are collected for eventual recycling. It may be possible to get significant numbers of bottles by purchasing the bottles from the recycling center. If the hassle of getting a sufficient number of recycled bottles is a problem, you can always purchase new bottles in bulk quantities from a number of competing bottle manufacturers. Indeed, you might be able to dig around in you garbage right now and find enough bottles to start your own flotation experiments!
Millions of these bottles are manufactured every day. They can be directly purchased in bulk from numerous competing manufacturers or they can be purchased from a recycling center or they can be obtained for free by asking for them. So even though you are going to need thousands of them, they will still be quite inexpensive
The plastic bottles are quite resistant to corrosive sea water. In addition, since thousands of bottles are being used for buoyancy, numerous individual bottles can lose their pressurization without affecting the overall buoyancy.
You can add surface area to your seastead incrementally.

The bottles are pressurized to about 2 atmospheres and assembled into 7 bottle hexagonal cells. The hexagonal cells are assembled into large sheets and stacked on top of one another to get the desired amount of buoyancy.

Now I will get into some of the details. The first issue is bottle pressurization. Why pressurize the bottles? Well, as unpressurised bottles are pushed deeper and deeper into water, the greater water pressure will start to collapse a bottle that is at one atmosphere of pressurization. Water pressure is approximately two atmospheres at a little less than 10 meters (32 feet for those of you who like English units.) As long as the bottle is pressurized to two atmospheres, it can be pushed under water to a depth of almost 10 meters before it starts to crumple.

You can pressurize the bottle any way you want. I can envision a special attachment that grabs onto the bottle lip, makes an air tight seal, pressurizes the bottle, screws on the bottle cap, and releases the bottle. Unfortunately, such an attachment sounds pretty expensive to me. I want a low technology solution. My alternative proposal (I have not tried this yet) is that you buy a chunk of dry ice and some nice thick gloves. You break off small pieces of the dry ice. You drop a small piece of dry ice into each bottle and screw the cap on. Eventually the dry ice sublimates and pressurizes the bottle. If the piece you drop in is too big, well, the bottle will pop (sort of like a balloon) and you need to get another bottle. What ever dry ice is left over can be thrown into a punch bowl to produce a really neat bubbling punch! Anyhow, it does not matter how you pressurize the bottles just so long as they are pressurized.

The next trick is to band the bottles together into a hexagonal bottle grids. My preference is that the bottles point down. That way if the cap leaks pressure, the inverted nature of the bottle will still displace the required amount of water. The bottle grid consists of seven bottles arranged in a hexagon as shown below:

7 Bottle Hexagon Cell
The bottles are attached to one another using nylon fishing line and a little dab of hot glue to prevent the knot from coming loose. The fishing line is wound around each bottle by 420 degrees to ensure that the bottles are firmly attached and so that the hexagon cells can be nestled next to one another without bumping into the fishing line. In addition, for the stacking step, the lips around the bottle necks are going to get in the way, so they need to be clipped off using some tin snips.

The bottle can be stack on top of one another by simply ensuring that the necks of top layer fit into the interstices of the lower layer as is shown in the top view below:

Top View of Hexagon Cell Stacking
Note how the bottle necks fit directly into the bottle interstices on the layer below. While gravity and the buoyancy of the lower bottles pushing up should be adequate to keep the bottles joined together, it seems prudent to wrap a little fishing line around them all to ensure that the stay together. A cross-sectional view of some bottles stacked on top of one another is shown below:

There is an issue of how to design the sides of the flotation. If there is a flat side, the ocean waves will hit the side and splash up. Flat sides will probably have to be built up into fairly high walls to prevent the ocean waves from broaching the walls and spilling plant killing salt water all over your crops. An alternative is to put a sloping barrier around the perimeter so that the ocean waves will break and dissipate as they climb the slope. Probably some combination of the two is what will ultimately be adopted.

Flotation Edge

As I was researching sea structures I ran across the book Materials for Marine Systems and Structures edited by Dennis Hasson and C. Robert Crow [Hasson1988]. This book devotes an entire chapter to the topic of biofouling -- plant life attaching itself to your flotation device. In other words -- barnacles on your bottom! Basically, biofouling occurs in two steps -- microfouling followed by macrofouling. Microfouling is the attachment single celled organisms to the surface. Macrofouling is the attachment of larger organisms such as barnacles and mussels. There is a chart on page 105 that suggests that macrofouling is strongly dependent on proximity to the shore. The further you are from shore, the less of a problem it is. If macrofouling persists, according to the book on page 115, chlorine is an effective biocide:

There is no consensus about the concentration of chlorine needed to control macrofouling. Similarly, no agreement has been reached about the relative advantages of low-level continuous chlorination compared to intermittent chlorination and the application rates depend on a variety of factors, including the predominant organisms, growth rates, location, season, and water temperature. In general, the soft macrofouling organisms can be controlled by intermittent chlorination at a level of 1.0mg/L residual chlorine for one hour out of every eight hours. Hardshelled foulers including barnacles and mussels, require continuous discharge of low-level chlorination -- 0.25-0.5mg/L of free residual chlorine.
If biofouling becomes a major problem for the seastead, a system for chlorinating the water around the seastead may need to be developed. Since chlorine is a nasty chemical to deal with, I sure hope that macrofouling does not become a problem for the deep seastead.

There are a number of issues associated with transporting the hexagon cells to the seastead assembly site, assembling them into a large floating area and then floating them out into the ocean. I am going to leave these issues unanswered because I think some experimentation is going to be needed to figure out the best answers for these issues. Let me just say that none of the problems look difficult to solve.


Once you have your flotation surface sitting in the water, it is time to cover it with dirt! First, we put a layer of 5 mil black plastic on top of the bottle ends. Second, we apply a layer of mixed stones and gravel on top of the first plastic layer. We rake the stones and gravel into squares with sloping sides and a depression in the center as shown below:

Top View of Gravel Sloping
The depression in the center are where we are going to collect fresh water that manages to seep through the upper layers of soil. Third, we apply another layer of 5 mil black plastic on top of the sloping squares. This layer of plastic prevents fresh water from seeping all the way through and dripping into the ocean and is shown below:
Side View of Gravel Rows
Fourth we drop some drop some water level sensors with pumps into the depressions. These devices are discussed in the fresh water management section below. Finally, we put some more gravel on top of the plastic followed by layers sand and soil until we have about half a meter (say 18 inches) of soil. This should provide an adequate layer of soil for most crops and vegetation.

If you want to plant trees, a significantly greater amount of soil depth is needed and correspondingly greater amount of flotation under the heavier soil load is required.

Self Sufficiency

Now that we have the prepared the surface of our flotation with a layer of soil, we can start to build the remainder of our seastead on top of it. There are numerous books published on the topic of being self sufficient and living off the land. The one I used was Building for Self Sufficiency by Robin Clarke [Clarke1976].

There is a decision we have to make about just how self sufficent we want to be. The more self sufficient we are, the less material we have to import into our seastead. The initial seastead will probably be rather small, so they will not be as self sufficient as the ones built later on.

There are two major differences that must be dealt with as self sufficiency books are applied to seastead technology. First, even though the seastead is surrounded by water, fresh water is going to have to be tightly managed. We do not have the option of tapping into a stream or drilling a well to get unlimited supplies of fresh water. Fresh water management is covered in greater detail later in the water section below. Second, surface area is going to be at a premium. Every square meter of land is going to require at least a hundred recycled beverage bottles to support it. Large meandering structures that occupy lots of space are not going to be viable in early seasteads.

I should comment that most of these self-sufficiency books start out with a preface that I will paraphrase as `humanity is running out of energy and resources; thus, we must change our evil high technology ways and go back to basic living off the land.' These statements should not be taken at face value, because many of them are not supported by scientific evidence. For example the inflation adjusted cost of energy and resources has continually declined when measured over periods of greater than ten years. A more balanced view of energy and resources can be found in The True State of the Planet a compendium of papers written by ten environmental scientists who publish in peer reviewed journals. The True State of the Planet is edited by Ronald Bailey [Bailey1995]. A number of the energy books I reference below suffer from the same basic flaw, however, once you get past the preface and first chapter of these various books, they tend to be pretty reasonable.


The first issue that I delve into is food production. When it comes to food production it is necessary to decide how self-sufficient the food production should be. There is a spectrum of choices ranging from importing everything to producing everything locally. Realistically, the initial seasteads are unlikely to be a 100% self sufficient due to lack of available space and experience. For example, growing wheat for bread will take a fairly large amount of space; whereas importing a few bags of wheat is quite inexpensive and easily stored. A reasonable goal for an early seastead is to be self-sufficient in fruits and vegetables. The remaining food staples can be imported.

When it comes to growing food, there is either standard soil based gardening or soil less hydroponic technology. To keep things relatively simple, I suggest starting with regular soil based gardening and branch out to hydroponic technology at a later date.

There is a long history of people supplementing their diet with home grown vegetables. During World War II, these gardens were called `Victory Gardens' and the name has stuck ever since. When I was digging around looking for books on victory gardens I ran across the book Square Foot Gardening by Mel Bartholomew [Bartholomew1981]. What I like about this book is that it tries to minimize the amount of time spent in the garden. Most other books seem to focus on gardening as a hobby and tend to soak up as much time as they can get.

The square foot gardening method espoused by Bartholomew starts by asking how much food do you want to grow. Next, the system figures out how much area you are going to need. The book has a heavy emphasis on vertical gardening by training plants (like peas and beans) to grow up vertical strings. Vertical gardening makes a great deal of sense on the seastead where land is at a premium. The garden is organized as a grid rather than long rows. Everything is measured in 1 foot squares. Then you plant the squares at the right times of the season for the plants to reach maturity. The food is harvested, the plain remains are composted and you do it all over again. The goal of square foot gardening is to spend just a few minutes a day on garden maintenance.

The only real disadvantage of soil based gardening is that it requires soil which must be imported to your homestead. Hydroponic food production allows you to grow food without importing soil. My reference on this topic is Hydroponic Food Production by Howard Resh [Resh1978]. A further advantage hydroponic gardening is that it can generate substantially more food in a given area than soil gardening. Given these advantages, it makes some sense to to start growing some plants hydroponically to gain experience with hydroponic technology. Eventually, over time hydroponic technology will displace some of the soil technology on the seastead. The amount displaced will ultimately depend upon how effective hydroponics are.

In addition to the vegetables, it makes sense to to have a number of fruit and nut trees planted on seastead to provide a regular supply of fruits and nuts. Since trees require more than half a meter of soil, it may be necessary to grow the trees in raised tubs. These raised tubs will be heavy, so it may be necessary to add additional flotation bottles underneath the tree tubs.

One real advantage that the seastead has when it comes to growing crops is that it is possible to reduce or eliminate weeds and insect pests. This is extremely difficult to do on land, since the weeds and pests are just blown across the property boundary. With a seastead, care can be taken to try and minimize the number of insects and weeds that take hold on the seastead. By immediately removing any unwanted pests and weeds whenever they are encountered, it is possible to get to a state where they have all been eradicated.

Once a crop has been harvested, the plant remains can be through into a compost heap. Over time a compost heap will generate new soil that can be added to the seastead soil. Composting is covered in both Building for Self-Sufficiency and Square Foot Gardening.


Now it is time to switch focus over to fresh water management. Despite being in the middle of an ocean, obtaining and retaining an adequate supply of fresh water is going to require some careful thought and implementation.

Below some various grades of water are defined:

Distilled Water
Distilled water is water that has desalinated by evaporation and recondensation. It is tends to be quite flat to drink. Distilled water can be aerated to improve its flavor.
Potable Water
Potable water is water that is clean enough to be directly ingested and has enough air and minerals mixed in that it `tastes good'.
Rain Water
Rain water is water that has been collected from rain fall. It may have a little dust mixed in with it that should be filtered out prior to drinking.
Grey Water
Grey water is water that has been used once for either washing, bathing, or showering. It tends to have a small amount soap mixed in with it. Grey water can readily be used to water vegetation.
Black Water
Black water is water that has bodily waste mixed in it, either urine or excrement. With some work black water can be neutralized to the extent that it can be mixed in with other grey water for vegetation watering.
The seastead will have a bunch of plumbing to move the various kinds of water around.

There will be a continual loss of fresh water due to evaporation and slow leaking. This means that the fresh water needs to be replenished. There are four possibilities for water replenishment -- rain water collection, distilling sea water into fresh water, reverse osmosis of sea water into fresh water, and importing fresh water. Of the four, importing fresh water seems the least practical and rain water collection seems the most practical.

Rain water collection is the simplest means for replenishing fresh water. By putting gutters on roofs and solar collectors we can directly route rain run-off into some cisterns. It is inevitable that dust will get mixed in with the runoff. A simple filter can be used to filter the dust out in order to make the rain water into potable water. In addition to gutters, the seastead has been carefully designed to collect all water that seeps through the soil. With some additional filtering, it should be possible to filter this water to remove the soil particles and convert it into potable water.

If the seastead is parked in area that does not get regular rain storms an alternative method of fresh water replenishment is needed. Either sea water distillation or reverse osmosis will work. Both forms of sea water reclamation require pretty hefty amounts of power. Distillation can be done with solar evaporation trays and condensers; whereas reverse osmosis runs off of electricity.

The soil has been carefully designed to have collection depressions for collecting any fresh water that seeps through. A device that is a combined water level sensor and a small electric pump can be placed at each depression. When the depression starts to fill up with water, the water level sensor triggers and the pump starts to pump the water away. These combined pump/water level sensors will have to be carefully designed to last a long time; otherwise, they will have to constantly dug up and replaced. After a rain storm the resultant rain water run off can be pumped out from under the soil and into a rain water cistern. It may make sense to direct the soil rain run off to a grey water cistern and the gutter run off to a potable water cistern.

To further conserve water, all crops and landscape vegetation should be irrigated with drip irrigation. To further conserve water, the irrigation system should be run at night to reduce evaporation due to sunlight.

The dwelling should have both black water and grey water drainage systems. The black water drain is connected to the toilets and the grey water is connected to the sinks, showers and baths. The grey water can be lightly treated and then directed to a grey water storage tank for subsequent crop and landscape watering. The black water drainage needs to be treated before it can be reused. One possibility is to use a septic tank. Another possibility is to use algae treatment ponds. Somebody (not me) is going to have to figure it all out.

One concern that must be dealt with is salt water contamination of the soil. As waves crash in the ocean around the seastead, small droplets of ocean water are formed that are blown around by the wind. These small droplets can land on the soil and slowly increase the soil salinity. Once the soil becomes too salty, crops will no longer grow. One solution is to do all crop growing in covered greenhouses on the seastead. I could not find any reference that would give me an idea of how serious a problem salt contamination will be.


Our seastead is going to need some power to run various tools and appliances. The Aquarius project proposed by the Millennial Foundation proposes to use OTEC (Ocean Thermal Energy Conversion) technology for energy production. There are numerous advantages to OTEC technology -- it works night and day, it brings nutrient rich water to the surface, and it produces fresh water as a side effect of its operation. Unfortunately, it has some problems too -- it is big, capital intensive, and is currently only available in prototype form. There are other workable alternatives that are both less capital intensive and more technologically mature -- solar power, wind power, and wave power. (Nuclear power is yet another alternative, but it is extremely capital intensive and politically difficult; in terms of seasteading, nuclear power makes OTEC technology look easy.)

Basically all of the alternative power sources have one problem in common -- the power is intermittent. Solar power does not work a night, wind power does not work when the winds are calm, and wave power does not work when the seas are calm. The only effective solution to this problem is collect and store excess energy for times when power generation is not available. For now, the most mature technology for storing energy appears to be electro chemical batteries. Since we are going to need a battery system anyway, it means we can use a combination of solar, wind, and wave power as suits our needs.

Solar Power

There are a variety of different forms of solar power -- photovoltaic, solar heating, solar dynamic, etc. For this paper, I am going to focus on photovoltaic power.

Photovoltaic (i.e. solar cells) technology was originally developed to supply power to satellites in outer space, a remote and hostile environment. Currently, photovoltaic power can make economic sense for remote areas that do not have a connection to the electric power grid (like seasteading.) There is now a large body of practical experience with photovoltaic power that can be applied to our seastead application. The reference I used was The New Solar Electric Home by Joel Davidson [Davidson1987]; I am sure there are plenty of other appropriate alternative books on the subject. Like the self-sufficiency books above, each of the solar power books tends to have the same preface about how we are running out of energy. As usual, please discount the preface and first chapter and move onto the rest of the book, which is typically quite pragmatic.

Photovoltaics have a number of disadvantages:

Photovoltaic panels are expensive. They keep coming down in price, but they are still not cheap.
Even the most efficient photovoltaic cells have only recently started to achieve conversion efficiencies over 30% and these are horrendously expensive. The commercially available solar panels have conversion efficiencies in the 8-15% range. This relatively low energy conversion efficiency means you need more solar panels to achieve the desired level of power generation.
Battery Storage Required
Since the sun does not shine at night, there is no power coming in from the solar panels at night. To work around this problem, the it is necessary to collect additional energy during the day and store it for night time use. The most common energy storage method is to use a bank of bateries. The batteries are expensive and the extra energy collection increases costs as well.
Despite these disadvantages, they have a proven track record for remote power generation.

Wind Power

Like solar power, wind power is a fairly mature technology that has been around for quite a while. When people think of wind power, the vision of the wind powered pump on a tower on a farm comes to mind. There are a number of more modern wind turbine designs as well. The reference I used for wind power was Harnessing the Wind for Home Energy by Dermot McGuigan [McGuigan1978]; as for photovoltaics, there are numerous appropriate alternative books on the subject. Again, most of these books start out with a statement of the form `we are running out of energy' that should be discounted.

Wind power has one major advantage over photovoltaic generation -- 24-hour a day power extraction is possible. While there are times when the wind dies down, it possible to place a seastead in a location where that occurs infrequently. With continuous power extraction, a large power storage system based on batteries can possibly be avoided.

Wind mills can be broken into two broad catagories that are defined as follows from the book:

Horizontal Axis
Where the propeller (or rotor) on a horizontal shaft or axis moves in a plane perpendicular to the direction of the wind. This includes multi-blade, four-arm and high-speed propeller types
Vertical Axis
Where the rotor on a vertical shaft or axis has its effective wind-catching surface moving in the direction of the wind. This includes the more recentlhy developed Darrieous and Savonius rotors
The standard rotor on a tower with a vane coming out the back is a horizontal axis wind mill. Vertical axis wind mills are not as common, but are commonly referred to as `egg beaters' or `oil drums'.

It can be shown that windmill are operating at peak energy efficiency when they have slowed the wind down by about two thirds. Thus, wind mills have to let some of the wind get through.

The seastead is free to use any form of wind mill; they all work with varying degrees of efficiency. My current favorite is the Savonius rotor, sometimes referred to as an oil drum rotor. A cross section of a Savonius rotor is shown below:

A Savonius Rotor Cross Section
Of all the wind mill generators available, the Savonius rotor is the least efficient. However, it also looks like its very easy to fabricate, since many Savonius rotors are manufactured out of old oil drums. Ultimately, what matters is not wind mill efficiency, but cost times efficiency. If cost is sufficiently low, additional power is obtained by simply erecting additional wind mills. When horizontal space for the wind mills runs out, it turns out that Savonius rotors can be stacked on top of one another.

There is one additional disadvantage associated with wind power. As the wind blows through the wind mill, most of the extracted energy is being converted to electricity. However, some of the wind power is pushing against the wind mill and causing the seastead to be blown with the wind. Some experiments will need to be performed with wind power to figure out how severe the wind pushing problem is.

Wave Power

As I was digging around in the alternative energy section of the library that I use, I came across a book with the interesting title of Power From the Waves by David Ross [Ross1995]. That book exposed me to the interesting concept of extracting energy from wave motion. Obviously, the middle of an ocean is a mighty good place to find a bunch of waves. Unfortunately, the book by Ross largely chronicles the efforts to date to extract wave energy in Great Britain to be feed into the power grid. Most of the designs are pretty capital intensive and, hence, are not very appropriate for an inexpensive seastead. However, further research uncovered a book called Ocean Wave Energy Conversion by Michael McCormick [McCormick1981]. Again, most of the technology described in the book is quite capital intensive and, hence, not appropriate for the inexpensive seastead. However, on pages 110-117, an ingenious devise called the Russell Rectifier is described and a low cost implementation may be available for the seastead.

If you have had any experience with electronic circuitry, the Russell rectifier is the hydrolic equivalent to a two diode electronic rectification circuit. A diagram of a Russell rectifier can be found below:

The system consists of two water reservoirs which I have respectively called the "high water reservoir" and the "low water reservoir". The high water reservoir is connected to the ocean via a one way valve that only lets water flow from the ocean into the high water reservoir; this will only occur when the wave crest is higher that the water level in the high water reservoir. Similarly, the low water reservoir is connected to the ocean via a one way valve that only lets water flow from the low water reservoir to the ocean; again, this will only occur when the wave trough is below the level in the low water reservoir. A water turbine is connected between the two reservoirs that is driven by the difference in water levels of the two reservoirs. In general, the difference in water levels in the two reservoirs is directly proportional to the average ocean wave height. If the the seastead is currently experiencing 2 meter waves (i.e 6 feet for the metric impaired), the turbine will have a pressure head of 2 meters to work with.

While there are other wave extraction technologies that are probably more efficient at extracting energy from the waves, the Russell rectifier looks like it will be quite inexpensive to construct since it consists of a couple of simple reservoirs, some piping, some one way valves and a low pressure water turbine. The diagram below shows a few enhancements to Russell rectifier to make it easier to build and maintain.

Enhanced Russell Rectifier
The primary enhancement is that the valves and turbines have been moved to the top surface where they are more easily maintained. This way it is not necessary to dive over the edge just to inspect the valves and turbines. Instead, they are at `ground level' where they can easily be maintained. The one-way valves can have clear plastic view ports to allow easy inspection. In order to get the whole system started, you simply suck the air out to get the water siphoning around the system. This requires a small air valve at the highest point of each one way valve and the turbine. A small electric or manual vacuum pump can be used to remove the air to get the water siphoning through the system.

In addition, all of the pipes simply hang over the edge of the seastead into the ocean and over the edge of the reservoirs. A few moments of thought should convince you that all that matters is the difference in heights between the ocean and the reservoirs and not the actual placement of inlet and outlet pipes. As long as the pipes do not try to span more the about 10 meters vertically, the water can be moved around by the siphon effect.

So how cheaply can such a system be built? Well all of the piping can be done with inexpensive four inch PVC sewer pipe. The reservoirs can be made out of heat sealed plastic liners. By the way, it is not the end of the world if the reservoirs are a little leaky. The one way valves can be adapted from flapper valves used in toilet flush mechanisms. Some plastic insect screen can placed over the ocean inlet and outlet pipes to prevent fish and other debris from getting into the system and mucking things up. Everything can be glued together using PVC glue. The most expensive part of the system is the low pressure water turbine. Again, we do not need to have the world's most efficient water turbine; we can make trade offs between cost and efficiency. What is fun about this system is that someone could probably build a prototype using some garbage cans for reservoirs, some PVC sprinkler pipe for plumbing, and plunge a basketball into and out of a third garbage can to simulate waves. I suspect that is would be possible to build such a prototype and keep the entire cost of the system under $100. Any takers?

Are there any enhancements that can be applied to a Russell rectifier to improve its efficiency? Well, it probably the case that some sort of wave guide could be attached to the side of the sea stead to funnel the waves together. This would result in higher wave crests and ultimately a higher pressure head to drive the water turbine. For starters, these enhancements can be simply skipped over

Integrating the Power Systems

So the question arises, `Which power generation system should a seastead use?' The answer is probably a combination of the above. For right now, my bet is that the photovoltaic with storage battery technology is the most mature. Next, it would be interesting to put up some wind power generators to see if they can provide supplemental power generator for night time use. The Russell rectifier wave power generator is still basically speculative and should be prototyped to see if any useful amount of energy can be extracted from waves.

But what happens if you have a bunch of cloudy low wind days (i. e. reduced solar, wind and wave power?) Well, you either put up with the power failure (i.e. break out some lanterns and candles for lights) or you fire up your fossil fuel backup generator; these are the exact same options that most people face when their power grid power fails.

An integrated system of photovoltaic, wind, and wave power with battery storage and ultimately a fossil fuel backup generator should provide a very high level of power availability to the seastead. Such an integrated system should still cost substantially less than an OTEC system for the small and medium sized seastead.


Is the seastead a boat or an island?

If a seastead is an island, then is should be attached to the ocean floor to prevent it from moving around. Since the ocean floor is typically five miles from the ocean surface, attaching the seastead to the ocean floor is actually quite challenging. An other alternative is to have steerable propellers in a feedback look with GPS (Global Positioning System) that can push the the seastead to its desired location whenever it starts to drift off location.

My preference is to treat the seastead as a boat. For one thing, this means that all of the international law that applies to boats can be applied to a seastead. In addition, this means that when some bad weather is headed for the seastead, the seastead can try to avoid the bad weather. In addition, when supplies are low, the seastead can find a port and resupply itself. In all cases, an ocean going seastead will find it useful to have some sort of sea worthy boat to go between the seastead and shore.

The seastead is not designed to travel at high speeds. Thus, a number of trolling motors thrown over the side and hooked up to the electrical system will probably be adequate for seastead movement. Some sort of control system will be useful so that all of the propellers can be automatically lined up to point in the same direction without having to run around the seastead an manually point each one.

Once the first few seasteads have been deployed, they can aggregate into small sea villages by simply rendezvousing at a agreed upon location and lashing all the seastead into one bigger sea village. A little planning in advance can make this very easy. For example, let us assume seasteads are constructed to be rectangular in shape. If we place a short `road' across the narrow end of each seastead, the seasteads can be lined up so that the `road' can be used to access each seastead. This is shown in the figure below:

Simple Linear Community
Over time the sea communities will evolve from simply linear collections of seasteads, to grids and ultimately to sea cities. Whenever someone becomes annoyed with the current state of a seastead community, it is possible to just disconnect and take your seastead some place else.


There is not much that I would like to say about shelter. The shelter can be as simple as a tent or as complicated as a multilevel house. For initial seastead prototypes, my suggestion is to simply get some sort of inexpensive RV (recreational vehical) trailer and simply park it on one end of the seastead. An RV trailer provides sleeping accomedations, a small kitchen, a small bathroom, a place hang out, etc.

Since most RV trailers already have separate grey and black water tanks, it sould be very easy to integrate the trailer into the fresh water management system.

If it is desirable to watch television, a satellite dish can be installed to pick up satellite signals.

Making It Happen

This next section contains my opinions about the current state of affairs with regards to seasteading. Obviously, some people may not agree my opinions; they are welcome to write and publish their own paper outlining why they I am wrong.

The Expensive Way

Given enough money and will it is possible to build just about any kind of structure in the middle of the ocean that you can think about. Unfortunately, the tough part seems to be coming up with enough capital to make it happen. Let us examine the state of the Atlantis, Millennium, and New Utopia projects.

There has been very little visible progress with the Atlantis project for quite a while. It is quite likely that the Atlantis project is totally defunct.

The Aquarius portion of the New Millennium project seems to have gone through a number of phases:

Phase 1 (Enthusiasm):
Initial enthusiasm and excitement
Phase 2 (Replan):
Several replans to reduce project costs
Phase 3 (Bummer):
The growing realization that even the rescaled plans are still too expensive
Phase 4 (Slow Death):
Growing disenchantment with the whole project and a slow exodus of people working on the project. (This last part is still a bit speculative.)

The New Utopia project is probably roughly in phase 1. I predict that the New Utopia project will soon enter the redesign phase when when the desired levels of investment fail to materialize. (Remember, this is my prediction; other people are free to disagree!) I suspect that New Utopia will follow roughly the same path that the New Millennium project has.

Basically, the amount of capital required to build either Avalon or New Utopia is simply too high to be realistically raised. When an investor can put their money into an internet stock and double their money in 6 months, it is awfully hard to make a business case for a large artificial island that has no real intrinsic economic value.

Bootstrapping Seasteading

My proposed solution is to start very small and cheap and slowly build up to the desired goal of a fairly large artificial island in the middle of the ocean. By keeping the initial costs low, it is possible to build the initial versions and show potential investors what they are getting into at each step of the way.

I figure that an initial 1 acre seastead could be built by a relatively small dedicated team of volunteers for between $10,000 and $100,000 depending upon how hard people scrounge for things. While the this initial seastead would not be suitable for seasteading the high seas it could almost certainly survive indefinitely in a large harbor (e.g. San Francisco Bay or the Puget Sound) or a lake (e.g. Lake Michigan.)

If I had to select an initial site for a prototype seastead, I would probably select either the San Francisco Bay Area or the Puget Sound. Why? The computer industry has generated a simply astonishing number of individual multi-millionaires in the San Francisco Bay and Seattle areas. The future phases of seastead development could definitely benefit from the positive attention of a few millionaires. By locating the initial seastead prototype in one of these two areas, it is far more likely that one of these multi-millionaires will become interested in the seasteading project.

For the sake of argument, let us hypothesize that a team of 20 people from around the United States decide to get interested in a seastead prototype. These 20 people commit $500 towards the project. Most people spend well over $500 a year on their personal hobbies (e.g. RC planes, model trains, etc.) This gives the project a $10,000 budget to play with. Since $10,000 is not much money, it will have to be spent very carefully.

The next step is to identify a staging area. A staging area has some property at which materials can temporarily be stored. It has a pier that goes out into a body of water of sufficient depth that the prototype seastead will not run aground. Furthermore, the staging area needs to be able to park the seastead for years at time as it undergoes development. With a budget of $10,000, an outright purchase of the staging area seems unlikely. Some sort of deal will be required.

In parallel with the staging area, a number of small experiments can be performed. A small number of hexagon cells can be manufactured and tested for buoyancy, interconnect properties, and the like. Somebody who has a back yard can lay a bunch of beverage bottles on end, and see how well the plastic-gravel-plastic technology works for building up a soil base. Someone can figure out the water level sensor and pump system for moving water water at the bottom of the soil depressions around. One person each can experiment with photovoltaic energy generation, wind energy generation, and wave energy generation. A lot of additional research can take place -- how does a septic tank work?, how much area is required to be self sufficient in fruits and vegetables?, etc. One person can be a librarian who collects books and articles that are relevant to the project.

After all of the initial experiments and research have been completed and the staging area has been selected it is possible for the team to design the first prototype seastead. A complete budget is assembled to figure out what everything is going to cost, staging area costs, materials, any special labor costs, and special tools, etc. Now them moment of truth has arrived. Is there enough money in the budget? If it is close, perhaps the team members can kick in some additional funds. If it is way off, it may be necessary to scale back the seastead plans some and try again. Eventually a coherent prototype seastead design and a realistic budget comes out of this process.

Now comes a lot of rewarding hard work. Probably, the team members will assemble some number of hexagon cells at their respective homes and apartments. Plans are made to transfer all of the cells to the staging area. The people who live closest to the staging area will be able to make multiple hexagon cell trips. The rolls of plastic sheet, piles of stones, gravel and sand arrive at the staging area. Finally, the materials have all arrived and it is time for everybody to synchronize their vacations to arrive at the staging area to build the seastead.

When everybody arrives, the hexagon cells are put into the water and stacked on top one another. A prebuilt sloping ramp is used to get from the end of the pier to the top of the flotation. The plastic sheeting is spread out. A lot of wheel barrow trips are made to get the stones on top of the flotation. The stones are graded, additional plastic is spread down. The level sensors and pumps are put into the water collection depressions. More gravel, sand and soil is spread down. The flotation is starting to sink into the water from the weight of the stones, gravel and soil. As with any prototype effort, problems crop up and are solved on the spot. Eventually, after a week or two, the prototype seastead is sitting there in the water, and it is ready for the first person to sleep on it over night.

Now comes a period of a year or two where people come out to the prototype seastead and to tend the garden, add features, fix problems that develop, etc. In addition, now that there is a seastead to actually look at, some public relations can be done. Publish a few papers about the entire project. Invite the local newspapers to come on out for a tour. Indeed, invite the general public to come on out for one weekend a month. Charge an admission fee to recoup some of the expenses. Use the general public tours and public relations efforts to recruit more people to the cause. If you are lucky some multi-millionaire will get really interested in the project; if not, well at least you tried.

After the first prototype has been built and tested for a couple of years, it is time to take all of that experience and design the second prototype. The second prototype has a goal of being a sea worthy seastead that can be taken out into the middle of the ocean. Are recycled beverage bottles really going to work for a sea going seastead? How serious is salt contamination of the soil? The second seastead will probably cost about ten times what the first one cost. But the first one has generated enough interest in the public that it will probably be possible to raise ten times the money.

This process of building prototype seasteads continues until somebody comes along and says `I think it makes good business sense to form a company that builds seasteads and sell them.' Success! Now the seastead technology is going mainstream! I will leave the story at this juncture.

The Choice Is Yours

Let us compare this strategy with the strategies being employed by the Atlantis, Millennium, and New Utopia projects. All three of these projects require significant up front investment from investors. Which strategy do you think has a greater chance of happening? A bootstrapping process from small prototype seasteads or going straight to the ultimate city on an artificial island that skips all the intermediate steps? My opinion is that the bootstrapping process is far more likely to succeed.


In summary, enough technology already exists to create a viable seastead. Flotation can be accomplished using thousands of recycled 2-liter beverage bottles. Standard gardening techniques can be used to grow fruits and vegetables. A combination of solar, wind, and wave generators can be used to provide locally generated power. Off the shelf trolling motors can be used to provide seastead propulsion. A commercially manufactured RV trailer provides a perfectly workable shelter containing a bathrwoom, kitchen and sleeping accomidations. No expensive R&D on seacrete or OTEC is required to make the seastead a reality.

By starting with small prototype seasteads, and slowly working towards larger and larger ones, it is possible to avoid requiring huge cash infusions to complete the project. Instead, each stage of seastead development uses the prior stage of development to reduce risk and increase investor confidence.


I would like to acknowledge that I found both the Atlantis project and Millennial project to be the primary inspiration for even thinking about the concept of seasteading. I did not discover the New Utopia project until most of the ideas in this paper had already solidified.


Ronald Bailey: 1995. The True State of the Planet (New York: Simon & Shuster -- Free Press) ISBN: 0-02-874010-6
Mel Bartholomew: 1981. Square Foot Gardening (Emmaus PA: Rodale Press) ISBN: 0-87857-341-0
Robin Clarke: 1976. Building for Self Sufficiency (New York: Universe Books) ISBN: 0-87663-945-7
Davidson, Joel: 1987. The New Solar Electric Home (Ann Arbor: AATEC Publications) ISBN: 0-937948-09-8.
G. Ford, C. Niblett, and L. Walker: 1987. The Future for Ocean Technology (London: Frances Pinter) ISBN: 0-86187-522-2
Dennis F. Hasson, and C. Robert Crowe (ed.): 1988. Materials for Marine Systems and Structures (London: Academic Press) ISBN: 0-12-341828-3)
Michael P. McCormick: 1981. Ocean Wave Energy Conversion (New York: John Wiley & Sons) ISBN: 0-471-08543-X
Dermot. McGuigan: 1978. Harnessing the Wind for Home Energy (Charlotte VE: Garden Way Publishing) ISBN: 0-88266-117
Howard M. Resh: 1978. Hydroponic Food Production (Santa Barbara: Woodbridge Press) ISBN: 0-912800-54-2 LCCCN: 78-23468
David Ross: 1995. Power From the Waves (New York: Oxford University Press) ISBN: 0-19-856511-9
Marshall T. Savage: 1992. The Millennial Project: Colonizing the Galaxy in Eight Easy Steps (Denver: Empyrean Pub.) ISBN: 0-316-77163-5. LCCCN:94-15965


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